diff --git a/100+ Python challenging programming exercises.txt b/100+ Python challenging programming exercises.md
similarity index 79%
rename from 100+ Python challenging programming exercises.txt
rename to 100+ Python challenging programming exercises.md
index 97af5aaf..a08e260c 100644
--- a/100+ Python challenging programming exercises.txt	
+++ b/100+ Python challenging programming exercises.md	
@@ -1,46 +1,42 @@
-100+ Python challenging programming exercises
+# 100+ Python challenging programming exercises
 
-1.	Level description
-Level	Description
-Level 1	Beginner means someone who has just gone through an introductory Python course. He can solve some problems with 1 or 2 Python classes or functions. Normally, the answers could directly be found in the textbooks.
-Level 2	Intermediate means someone who has just learned Python, but already has a relatively strong programming background from before. He should be able to solve problems which may involve 3 or 3 Python classes or functions. The answers cannot be directly be found in the textbooks.
-Level 3	Advanced. He should use Python to solve more complex problem using more rich libraries functions and data structures and algorithms. He is supposed to solve the problem using several Python standard packages and advanced techniques.
+##	Level description
 
-2.	Problem template
+| Level	| Description |
+| --------------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
+| [Level1](#Level_1)   |	Beginner means someone who has just gone through an introductory Python course. He can solve some problems with 1 or 2 Python classes or functions. Normally, the answers could directly be found in the textbooks.|
+| [Level2](#Level_2)   |	Intermediate means someone who has just learned Python, but already has a relatively strong programming background from before. He should be able to solve problems which may involve 3 or 3 Python classes or functions. The answers cannot be directly be found in the textbooks. |
+| [Level3](#Level_3)   |	Advanced. He should use Python to solve more complex problem using more rich libraries functions and data structures and algorithms. He is supposed to solve the problem using several Python standard packages and advanced techniques. |
 
-#----------------------------------------#
-Question
-Hints
-Solution
+##	Problem template
 
-3.	Questions
+1. Question
+2. Hints
+3. Solution
 
-#----------------------------------------#
-Question 1
-Level 1
+##	Questions:
 
-Question:
+### Level_1
+
+ #### Question 1
 Write a program which will find all such numbers which are divisible by 7 but are not a multiple of 5,
 between 2000 and 3200 (both included).
 The numbers obtained should be printed in a comma-separated sequence on a single line.
 
-Hints: 
-Consider use range(#begin, #end) method
+**Hints:**
+Consider use `range(#begin, #end)` method
 
-Solution:
+**Solution:**
+``` python
 l=[]
 for i in range(2000, 3201):
-    if (i%7==0) and (i%5!=0):
+    if (i%7 == 0) and (i%5 != 0):
         l.append(str(i))
 
 print ','.join(l)
-#----------------------------------------#
-
-#----------------------------------------#
-Question 2
-Level 1
+```
 
-Question:
+ #### Question 2
 Write a program which can compute the factorial of a given numbers.
 The results should be printed in a comma-separated sequence on a single line.
 Suppose the following input is supplied to the program:
@@ -48,10 +44,11 @@ Suppose the following input is supplied to the program:
 Then, the output should be:
 40320
 
-Hints:
+**Hints:**
 In case of input data being supplied to the question, it should be assumed to be a console input.
 
-Solution:
+**Solution:**
+``` python
 def fact(x):
     if x == 0:
         return 1
@@ -59,37 +56,30 @@ def fact(x):
 
 x=int(raw_input())
 print fact(x)
-#----------------------------------------#
+```
 
-#----------------------------------------#
-Question 3
-Level 1
-
-Question:
+#### Question 3
 With a given integral number n, write a program to generate a dictionary that contains (i, i*i) such that is an integral number between 1 and n (both included). and then the program should print the dictionary.
 Suppose the following input is supplied to the program:
 8
 Then, the output should be:
 {1: 1, 2: 4, 3: 9, 4: 16, 5: 25, 6: 36, 7: 49, 8: 64}
 
-Hints:
+**Hints:**
 In case of input data being supplied to the question, it should be assumed to be a console input.
-Consider use dict()
+Consider use `dict()`
 
-Solution:
-n=int(raw_input())
-d=dict()
+**Solution:**
+``` python
+n = int(raw_input())
+d = dict()
 for i in range(1,n+1):
-    d[i]=i*i
-
-print d
-#----------------------------------------#
+    d[i] = i*i
 
-#----------------------------------------#
-Question 4
-Level 1
+print(d)
+```
 
-Question:
+ #### Question 4
 Write a program which accepts a sequence of comma-separated numbers from console and generate a list and a tuple which contains every number.
 Suppose the following input is supplied to the program:
 34,67,55,33,12,98
@@ -97,32 +87,30 @@ Then, the output should be:
 ['34', '67', '55', '33', '12', '98']
 ('34', '67', '55', '33', '12', '98')
 
-Hints:
+**Hints:**
 In case of input data being supplied to the question, it should be assumed to be a console input.
 tuple() method can convert list to tuple
 
-Solution:
-values=raw_input()
-l=values.split(",")
-t=tuple(l)
-print l
-print t
-#----------------------------------------#
-
-#----------------------------------------#
-Question 5
-Level 1
+**Solution:** ``` python
+``` python
+values = raw_input()
+l = values.split(",")
+t = tuple(l)
+print(l)
+print(t)
+```
 
-Question:
+ #### Question 5
 Define a class which has at least two methods:
 getString: to get a string from console input
 printString: to print the string in upper case.
 Also please include simple test function to test the class methods.
 
-Hints:
-Use __init__ method to construct some parameters
+**Hints:**
+Use `__init__` method to construct some parameters
 
-Solution:
+**Solution:**
+``` python
 class InputOutString(object):
     def __init__(self):
         self.s = ""
@@ -136,13 +124,80 @@ class InputOutString(object):
 strObj = InputOutString()
 strObj.getString()
 strObj.printString()
-#----------------------------------------#
+```
 
-#----------------------------------------#
-Question 6
-Level 2
+ #### Question 23
 
 Question:
+    Write a method which can calculate square value of number
+
+**Hints:**
+    Using the ** operator
+
+**Solution:**
+``` python
+def square(num):
+    return num ** 2
+
+print square(2)
+print square(3)
+```
+ #### Question 24
+
+Question:
+    Python has many built-in functions, and if you do not know how to use it, you can read document online or find some books. But Python has a built-in document function for every built-in functions.
+    Please write a program to print some Python built-in functions documents, such as abs(), int(), raw_input()
+    And add document for your own function
+    
+**Hints:**
+    The built-in document method is __doc__
+
+**Solution:**
+``` python
+print abs.__doc__
+print int.__doc__
+print raw_input.__doc__
+
+def square(num):
+    '''Return the square value of the input number.
+    
+    The input number must be integer.
+    '''
+    return num ** 2
+
+print square(2)
+print square.__doc__
+```
+
+ #### Question 25
+Define a class, which have a class parameter and have a same instance parameter.
+
+**Hints:**
+    Define a instance parameter, need add it in __init__ method
+    You can init a object with construct parameter or set the value later
+
+**Solution:** 
+``` python
+class Person:
+    # Define the class parameter "name"
+    name = "Person"
+    
+    def __init__(self, name = None):
+        # self.name is the instance parameter
+        self.name = name
+
+jeffrey = Person("Jeffrey")
+print "%s name is %s" % (Person.name, jeffrey.name)
+
+nico = Person()
+nico.name = "Nico"
+print "%s name is %s" % (Person.name, nico.name)
+
+```
+
+### Level_2
+
+ #### Question 6
 Write a program that calculates and prints the value according to the given formula:
 Q = Square root of [(2 * C * D)/H]
 Following are the fixed values of C and H:
@@ -158,24 +213,20 @@ Hints:
 If the output received is in decimal form, it should be rounded off to its nearest value (for example, if the output received is 26.0, it should be printed as 26)
 In case of input data being supplied to the question, it should be assumed to be a console input. 
 
-Solution:
+**Solution:**
+``` python
 #!/usr/bin/env python
 import math
-c=50
-h=30
+c = 50
+h = 30
 value = []
-items=[x for x in raw_input().split(',')]
+items = [x for x in raw_input().split(',')]
 for d in items:
     value.append(str(int(round(math.sqrt(2*c*float(d)/h)))))
 
 print ','.join(value)
-#----------------------------------------#
-
-#----------------------------------------#
-Question 7
-Level 2
-
-Question:
+```
+ #### Question 7
 Write a program which takes 2 digits, X,Y as input and generates a 2-dimensional array. The element value in the i-th row and j-th column of the array should be i*j.
 Note: i=0,1.., X-1; j=0,1,¡­Y-1.
 Example
@@ -184,10 +235,11 @@ Suppose the following inputs are given to the program:
 Then, the output of the program should be:
 [[0, 0, 0, 0, 0], [0, 1, 2, 3, 4], [0, 2, 4, 6, 8]] 
 
-Hints:
+**Hints:**
 Note: In case of input data being supplied to the question, it should be assumed to be a console input in a comma-separated form.
 
-Solution:
+**Solution:**
+``` python
 input_str = raw_input()
 dimensions=[int(x) for x in input_str.split(',')]
 rowNum=dimensions[0]
@@ -199,33 +251,24 @@ for row in range(rowNum):
         multilist[row][col]= row*col
 
 print multilist
-#----------------------------------------#
-
-#----------------------------------------#
-Question 8
-Level 2
-
-Question:
+```
+ #### Question 8
 Write a program that accepts a comma separated sequence of words as input and prints the words in a comma-separated sequence after sorting them alphabetically.
 Suppose the following input is supplied to the program:
 without,hello,bag,world
 Then, the output should be:
 bag,hello,without,world
 
-Hints:
+**Hints:**
 In case of input data being supplied to the question, it should be assumed to be a console input.
 
-Solution:
+**Solution:** 
+``` python
 items=[x for x in raw_input().split(',')]
 items.sort()
 print ','.join(items)
-#----------------------------------------#
-
-#----------------------------------------#
-Question 9
-Level 2
-
-Question£º
+```
+ #### Question 9
 Write a program that accepts sequence of lines as input and prints the lines after making all characters in the sentence capitalized.
 Suppose the following input is supplied to the program:
 Hello world
@@ -234,10 +277,11 @@ Then, the output should be:
 HELLO WORLD
 PRACTICE MAKES PERFECT
 
-Hints:
+**Hints:**
 In case of input data being supplied to the question, it should be assumed to be a console input.
 
-Solution:
+**Solution:** 
+``` python
 lines = []
 while True:
     s = raw_input()
@@ -248,34 +292,28 @@ while True:
 
 for sentence in lines:
     print sentence
-#----------------------------------------#
-
-#----------------------------------------#
-Question 10
-Level 2
+```
 
-Question:
+#### Question 10
 Write a program that accepts a sequence of whitespace separated words as input and prints the words after removing all duplicate words and sorting them alphanumerically.
 Suppose the following input is supplied to the program:
 hello world and practice makes perfect and hello world again
 Then, the output should be:
 again and hello makes perfect practice world
 
-Hints:
+**Hints:**
 In case of input data being supplied to the question, it should be assumed to be a console input.
 We use set container to remove duplicated data automatically and then use sorted() to sort the data.
 
-Solution:
+**Solution:**
+``` python
 s = raw_input()
 words = [word for word in s.split(" ")]
 print " ".join(sorted(list(set(words))))
-#----------------------------------------#
+```
 
-#----------------------------------------#
-Question 11
-Level 2
 
-Question:
+#### Question 11
 Write a program which accepts a sequence of comma separated 4 digit binary numbers as its input and then check whether they are divisible by 5 or not. The numbers that are divisible by 5 are to be printed in a comma separated sequence.
 Example:
 0100,0011,1010,1001
@@ -283,10 +321,11 @@ Then the output should be:
 1010
 Notes: Assume the data is input by console.
 
-Hints:
+**Hints:**
 In case of input data being supplied to the question, it should be assumed to be a console input.
 
-Solution:
+**Solution:** ``` python
+``` python
 value = []
 items=[x for x in raw_input().split(',')]
 for p in items:
@@ -295,33 +334,27 @@ for p in items:
         value.append(p)
 
 print ','.join(value)
-#----------------------------------------#
-
-#----------------------------------------#
-Question 12
-Level 2
+```
 
-Question:
+#### Question 12
 Write a program, which will find all such numbers between 1000 and 3000 (both included) such that each digit of the number is an even number.
 The numbers obtained should be printed in a comma-separated sequence on a single line.
 
-Hints:
+**Hints:**
 In case of input data being supplied to the question, it should be assumed to be a console input.
 
-Solution:
+**Solution:**
+``` python
 values = []
 for i in range(1000, 3001):
     s = str(i)
     if (int(s[0])%2==0) and (int(s[1])%2==0) and (int(s[2])%2==0) and (int(s[3])%2==0):
         values.append(s)
 print ",".join(values)
-#----------------------------------------#
+```
 
-#----------------------------------------#
-Question 13
-Level 2
 
-Question:
+#### Question 13
 Write a program that accepts a sentence and calculate the number of letters and digits.
 Suppose the following input is supplied to the program:
 hello world! 123
@@ -329,10 +362,11 @@ Then, the output should be:
 LETTERS 10
 DIGITS 3
 
-Hints:
+**Hints:**
 In case of input data being supplied to the question, it should be assumed to be a console input.
 
-Solution:
+**Solution:**
+``` python
 s = raw_input()
 d={"DIGITS":0, "LETTERS":0}
 for c in s:
@@ -344,13 +378,9 @@ for c in s:
         pass
 print "LETTERS", d["LETTERS"]
 print "DIGITS", d["DIGITS"]
-#----------------------------------------#
+```
 
-#----------------------------------------#
-Question 14
-Level 2
-
-Question:
+#### Question 14
 Write a program that accepts a sentence and calculate the number of upper case letters and lower case letters.
 Suppose the following input is supplied to the program:
 Hello world!
@@ -358,10 +388,11 @@ Then, the output should be:
 UPPER CASE 1
 LOWER CASE 9
 
-Hints:
+**Hints:**
 In case of input data being supplied to the question, it should be assumed to be a console input.
 
-Solution:
+**Solution:** 
+``` python
 s = raw_input()
 d={"UPPER CASE":0, "LOWER CASE":0}
 for c in s:
@@ -373,55 +404,50 @@ for c in s:
         pass
 print "UPPER CASE", d["UPPER CASE"]
 print "LOWER CASE", d["LOWER CASE"]
-#----------------------------------------#
-
-#----------------------------------------#
-Question 15
-Level 2
+```
 
-Question:
+#### Question 15
 Write a program that computes the value of a+aa+aaa+aaaa with a given digit as the value of a.
 Suppose the following input is supplied to the program:
 9
 Then, the output should be:
 11106
 
-Hints:
+**Hints:**
 In case of input data being supplied to the question, it should be assumed to be a console input.
 
-Solution:
+**Solution:**
+``` python
 a = raw_input()
 n1 = int( "%s" % a )
 n2 = int( "%s%s" % (a,a) )
 n3 = int( "%s%s%s" % (a,a,a) )
 n4 = int( "%s%s%s%s" % (a,a,a,a) )
 print n1+n2+n3+n4
-#----------------------------------------#
+```
 
-#----------------------------------------#
-Question 16
-Level 2
 
-Question:
+#### Question 16
+
 Use a list comprehension to square each odd number in a list. The list is input by a sequence of comma-separated numbers.
 Suppose the following input is supplied to the program:
 1,2,3,4,5,6,7,8,9
 Then, the output should be:
 1,3,5,7,9
 
-Hints:
+**Hints:**
 In case of input data being supplied to the question, it should be assumed to be a console input.
 
-Solution:
+**Solution:**
+``` python
 values = raw_input()
 numbers = [x for x in values.split(",") if int(x)%2!=0]
 print ",".join(numbers)
-#----------------------------------------#
+``` 
+
+#### Question 17
 
-Question 17
-Level 2
 
-Question:
 Write a program that computes the net amount of a bank account based a transaction log from console input. The transaction log format is shown as following:
 D 100
 W 200
@@ -435,10 +461,11 @@ D 100
 Then, the output should be:
 500
 
-Hints:
+**Hints:**
 In case of input data being supplied to the question, it should be assumed to be a console input.
 
-Solution:
+**Solution:**
+``` python
 netAmount = 0
 while True:
     s = raw_input()
@@ -454,21 +481,21 @@ while True:
     else:
         pass
 print netAmount
-#----------------------------------------#
+```
+
+### Level_3
+#### Question 18
 
-#----------------------------------------#
-Question 18
-Level 3
 
 Question:
 A website requires the users to input username and password to register. Write a program to check the validity of password input by users.
 Following are the criteria for checking the password:
 1. At least 1 letter between [a-z]
 2. At least 1 number between [0-9]
-1. At least 1 letter between [A-Z]
-3. At least 1 character from [$#@]
-4. Minimum length of transaction password: 6
-5. Maximum length of transaction password: 12
+3. At least 1 letter between [A-Z]
+4. At least 1 character from [$#@]
+5. Minimum length of transaction password: 6
+6. Maximum length of transaction password: 12
 Your program should accept a sequence of comma separated passwords and will check them according to the above criteria. Passwords that match the criteria are to be printed, each separated by a comma.
 Example
 If the following passwords are given as input to the program:
@@ -476,10 +503,11 @@ ABd1234@1,a F1#,2w3E*,2We3345
 Then, the output of the program should be:
 ABd1234@1
 
-Hints:
+**Hints:**
 In case of input data being supplied to the question, it should be assumed to be a console input.
 
-Solutions:
+**Solution:** ``` python
+``` python
 import re
 value = []
 items=[x for x in raw_input().split(',')]
@@ -502,13 +530,10 @@ for p in items:
         pass
     value.append(p)
 print ",".join(value)
-#----------------------------------------#
+```
 
-#----------------------------------------#
-Question 19
-Level 3
+#### Question 19
 
-Question:
 You are required to write a program to sort the (name, age, height) tuples by ascending order where name is string, age and height are numbers. The tuples are input by console. The sort criteria is:
 1: Sort based on name;
 2: Then sort based on age;
@@ -523,11 +548,12 @@ Json,21,85
 Then, the output of the program should be:
 [('John', '20', '90'), ('Jony', '17', '91'), ('Jony', '17', '93'), ('Json', '21', '85'), ('Tom', '19', '80')]
 
-Hints:
+**Hints:**
 In case of input data being supplied to the question, it should be assumed to be a console input.
 We use itemgetter to enable multiple sort keys.
 
-Solutions:
+**Solution:**
+``` python
 from operator import itemgetter, attrgetter
 
 l = []
@@ -538,19 +564,17 @@ while True:
     l.append(tuple(s.split(",")))
 
 print sorted(l, key=itemgetter(0,1,2))
-#----------------------------------------#
 
-#----------------------------------------#
-Question 20
-Level 3
+```
 
-Question:
+ #### Question 20
 Define a class with a generator which can iterate the numbers, which are divisible by 7, between a given range 0 and n.
 
-Hints:
+**Hints:**
 Consider use yield
 
-Solution:
+**Solution:**
+``` python
 def putNumbers(n):
     i = 0
     while i<n:
@@ -561,13 +585,10 @@ def putNumbers(n):
 
 for i in reverse(100):
     print i
-#----------------------------------------#
+```
 
-#----------------------------------------#
-Question 21
-Level 3
 
-Question£º
+#### Question 21
 A robot moves in a plane starting from the original point (0,0). The robot can move toward UP, DOWN, LEFT and RIGHT with a given steps. The trace of robot movement is shown as the following:
 UP 5
 DOWN 3
@@ -584,10 +605,11 @@ RIGHT 2
 Then, the output of the program should be:
 2
 
-Hints:
+**Hints:**
 In case of input data being supplied to the question, it should be assumed to be a console input.
 
-Solution:
+**Solution:**
+``` python
 import math
 pos = [0,0]
 while True:
@@ -609,13 +631,10 @@ while True:
         pass
 
 print int(round(math.sqrt(pos[1]**2+pos[0]**2)))
-#----------------------------------------#
+```
 
-#----------------------------------------#
-Question 22
-Level 3
+#### Question 22
 
-Question:
 Write a program to compute the frequency of the words from the input. The output should output after sorting the key alphanumerically. 
 Suppose the following input is supplied to the program:
 New to Python or choosing between Python 2 and Python 3? Read Python 2 or Python 3.
@@ -632,10 +651,11 @@ choosing:1
 or:2
 to:1
 
-Hints
+**Hints:**
 In case of input data being supplied to the question, it should be assumed to be a console input.
 
-Solution:
+**Solution:**
+``` python
 freq = {}   # frequency of words in text
 line = raw_input()
 for word in line.split():
@@ -646,170 +666,94 @@ words.sort()
 
 for w in words:
     print "%s:%d" % (w,freq[w])
-#----------------------------------------#
-
-#----------------------------------------#
-Question 23
-level 1
-
-Question:
-    Write a method which can calculate square value of number
-
-Hints:
-    Using the ** operator
-
-Solution:
-def square(num):
-    return num ** 2
-
-print square(2)
-print square(3)
-#----------------------------------------#
-
-#----------------------------------------#
-Question 24
-Level 1
-
-Question:
-    Python has many built-in functions, and if you do not know how to use it, you can read document online or find some books. But Python has a built-in document function for every built-in functions.
-    Please write a program to print some Python built-in functions documents, such as abs(), int(), raw_input()
-    And add document for your own function
-    
-Hints:
-    The built-in document method is __doc__
-
-Solution:
-print abs.__doc__
-print int.__doc__
-print raw_input.__doc__
-
-def square(num):
-    '''Return the square value of the input number.
-    
-    The input number must be integer.
-    '''
-    return num ** 2
-
-print square(2)
-print square.__doc__
-#----------------------------------------#
-
-#----------------------------------------#
-Question 25
-Level 1
+```
 
-Question:
-    Define a class, which have a class parameter and have a same instance parameter.
-
-Hints:
-    Define a instance parameter, need add it in __init__ method
-    You can init a object with construct parameter or set the value later
 
-Solution:
-class Person:
-    # Define the class parameter "name"
-    name = "Person"
-    
-    def __init__(self, name = None):
-        # self.name is the instance parameter
-        self.name = name
-
-jeffrey = Person("Jeffrey")
-print "%s name is %s" % (Person.name, jeffrey.name)
-
-nico = Person()
-nico.name = "Nico"
-print "%s name is %s" % (Person.name, nico.name)
-#----------------------------------------#
+### Undefined Dificulty
 
-#----------------------------------------#
-Question:
+#### Question:
 Define a function which can compute the sum of two numbers.
 
-Hints:
+**Hints:**
 Define a function with two numbers as arguments. You can compute the sum in the function and return the value.
 
-Solution
+**Solution:**
+``` python
 def SumFunction(number1, number2):
 	return number1+number2
 
 print SumFunction(1,2)
-
-#----------------------------------------#
-Question:
+```
+ #### Question:
 Define a function that can convert a integer into a string and print it in console.
 
-Hints:
+**Hints:**
 
 Use str() to convert a number to string.
 
-Solution
+**Solution:** ``` python
+``` python
 def printValue(n):
 	print str(n)
 
 printValue(3)
-	
+```
 
-#----------------------------------------#
-Question:
+
+#### Question:
 Define a function that can convert a integer into a string and print it in console.
 
-Hints:
+**Hints:**
 
 Use str() to convert a number to string.
 
-Solution
+**Solution:** 
+``` python
+
 def printValue(n):
 	print str(n)
 
 printValue(3)
-
-#----------------------------------------#
-2.10
-
-Question:
+``` 
+#### Question:
 Define a function that can receive two integral numbers in string form and compute their sum and then print it in console.
 
-Hints:
+**Hints:**
 
 Use int() to convert a string to integer.
 
-Solution
+**Solution:** 
+``` python
 def printValue(s1,s2):
 	print int(s1)+int(s2)
 
 printValue("3","4") #7
+```
 
-
-#----------------------------------------#
-2.10
-
-
-Question:
+ #### Question:
 Define a function that can accept two strings as input and concatenate them and then print it in console.
 
-Hints:
+**Hints:**
 
 Use + to concatenate the strings
 
-Solution
+**Solution:** 
+``` python
 def printValue(s1,s2):
 	print s1+s2
 
 printValue("3","4") #34
 
-#----------------------------------------#
-2.10
-
-
-Question:
+```
+ #### Question:
 Define a function that can accept two strings as input and print the string with maximum length in console. If two strings have the same length, then the function should print al l strings line by line.
 
-Hints:
+**Hints:**
 
 Use len() function to get the length of a string
 
-Solution
+**Solution:** 
+``` python
 def printValue(s1,s2):
 	len1 = len(s1)
 	len2 = len(s2)
@@ -823,93 +767,76 @@ def printValue(s1,s2):
 		
 
 printValue("one","three")
-
-
-
-#----------------------------------------#
-2.10
-
-Question:
+``` 
+#### Question:
 Define a function that can accept an integer number as input and print the "It is an even number" if the number is even, otherwise print "It is an odd number".
 
-Hints:
+**Hints:**
 
 Use % operator to check if a number is even or odd.
 
-Solution
+**Solution:** 
+``` python
 def checkValue(n):
 	if n%2 == 0:
 		print "It is an even number"
 	else:
 		print "It is an odd number"
 		
-
 checkValue(7)
+```
 
-
-#----------------------------------------#
-2.10
-
-Question:
+ #### Question:
 Define a function which can print a dictionary where the keys are numbers between 1 and 3 (both included) and the values are square of keys.
 
-Hints:
+**Hints:**
 
 Use dict[key]=value pattern to put entry into a dictionary.
 Use ** operator to get power of a number.
 
-Solution
+**Solution:** 
+``` python
 def printDict():
 	d=dict()
 	d[1]=1
 	d[2]=2**2
 	d[3]=3**2
 	print d
-		
 
 printDict()
+```
 
-
-
-
-
-#----------------------------------------#
-2.10
-
-Question:
+ #### Question:
 Define a function which can print a dictionary where the keys are numbers between 1 and 20 (both included) and the values are square of keys.
 
-Hints:
+**Hints:**
 
 Use dict[key]=value pattern to put entry into a dictionary.
 Use ** operator to get power of a number.
 Use range() for loops.
 
-Solution
+**Solution:** 
+``` python
 def printDict():
 	d=dict()
 	for i in range(1,21):
 		d[i]=i**2
 	print d
 		
-
 printDict()
-
-
-#----------------------------------------#
-2.10
-
-Question:
+```
+ #### Question:
 Define a function which can generate a dictionary where the keys are numbers between 1 and 20 (both included) and the values are square of keys. The function should just print the values only.
 
-Hints:
+**Hints:**
 
 Use dict[key]=value pattern to put entry into a dictionary.
 Use ** operator to get power of a number.
 Use range() for loops.
 Use keys() to iterate keys in the dictionary. Also we can use item() to get key/value pairs.
 
-Solution
+**Solution:**
+``` python
 def printDict():
 	d=dict()
 	for i in range(1,21):
@@ -920,20 +847,19 @@ def printDict():
 
 printDict()
 
-#----------------------------------------#
-2.10
-
-Question:
+``` 
+#### Question:
 Define a function which can generate a dictionary where the keys are numbers between 1 and 20 (both included) and the values are square of keys. The function should just print the keys only.
 
-Hints:
+**Hints:**
 
 Use dict[key]=value pattern to put entry into a dictionary.
 Use ** operator to get power of a number.
 Use range() for loops.
 Use keys() to iterate keys in the dictionary. Also we can use item() to get key/value pairs.
 
-Solution
+**Solution:**
+``` python
 def printDict():
 	d=dict()
 	for i in range(1,21):
@@ -944,67 +870,59 @@ def printDict():
 
 printDict()
 
+```
 
-#----------------------------------------#
-2.10
-
-Question:
+ #### Question:
 Define a function which can generate and print a list where the values are square of numbers between 1 and 20 (both included).
 
-Hints:
+**Hints:**
 
 Use ** operator to get power of a number.
 Use range() for loops.
 Use list.append() to add values into a list.
 
-Solution
+**Solution:**
+ ``` python
 def printList():
 	li=list()
 	for i in range(1,21):
 		li.append(i**2)
 	print li
-		
-
 printList()
 
-#----------------------------------------#
-2.10
-
-Question:
+```
+#### Question:
 Define a function which can generate a list where the values are square of numbers between 1 and 20 (both included). Then the function needs to print the first 5 elements in the list.
 
-Hints:
+**Hints:**
 
 Use ** operator to get power of a number.
 Use range() for loops.
 Use list.append() to add values into a list.
 Use [n1:n2] to slice a list
 
-Solution
+**Solution:** 
+``` python
 def printList():
 	li=list()
 	for i in range(1,21):
 		li.append(i**2)
 	print li[:5]
-		
 
 printList()
-
-
-#----------------------------------------#
-2.10
-
-Question:
+```
+ #### Question:
 Define a function which can generate a list where the values are square of numbers between 1 and 20 (both included). Then the function needs to print the last 5 elements in the list.
 
-Hints:
+**Hints:**
 
 Use ** operator to get power of a number.
 Use range() for loops.
 Use list.append() to add values into a list.
 Use [n1:n2] to slice a list
 
-Solution
+**Solution:** 
+``` python
 def printList():
 	li=list()
 	for i in range(1,21):
@@ -1013,22 +931,20 @@ def printList():
 		
 
 printList()
+```
 
-
-#----------------------------------------#
-2.10
-
-Question:
+ #### Question:
 Define a function which can generate a list where the values are square of numbers between 1 and 20 (both included). Then the function needs to print all values except the first 5 elements in the list.
 
-Hints:
+**Hints:**
 
 Use ** operator to get power of a number.
 Use range() for loops.
 Use list.append() to add values into a list.
 Use [n1:n2] to slice a list
 
-Solution
+**Solution:** 
+``` python
 def printList():
 	li=list()
 	for i in range(1,21):
@@ -1037,22 +953,19 @@ def printList():
 		
 
 printList()
-
-
-#----------------------------------------#
-2.10
-
-Question:
+``` 
+#### Question:
 Define a function which can generate and print a tuple where the value are square of numbers between 1 and 20 (both included). 
 
-Hints:
+**Hints:**
 
 Use ** operator to get power of a number.
 Use range() for loops.
 Use list.append() to add values into a list.
 Use tuple() to get a tuple from a list.
 
-Solution
+**Solution:** 
+``` python
 def printTuple():
 	li=list()
 	for i in range(1,21):
@@ -1060,39 +973,34 @@ def printTuple():
 	print tuple(li)
 		
 printTuple()
+```
 
-
-
-#----------------------------------------#
-2.10
-
-Question:
+#### Question:
 With a given tuple (1,2,3,4,5,6,7,8,9,10), write a program to print the first half values in one line and the last half values in one line. 
 
-Hints:
+**Hints:**
 
 Use [n1:n2] notation to get a slice from a tuple.
 
-Solution
+**Solution:** 
+``` python
 tp=(1,2,3,4,5,6,7,8,9,10)
 tp1=tp[:5]
 tp2=tp[5:]
 print tp1
 print tp2
 
-
-#----------------------------------------#
-2.10
-
-Question:
+``` 
+#### Question:
 Write a program to generate and print another tuple whose values are even numbers in the given tuple (1,2,3,4,5,6,7,8,9,10). 
 
-Hints:
+**Hints:**
 
 Use "for" to iterate the tuple
 Use tuple() to generate a tuple from a list.
 
-Solution
+**Solution:** 
+``` python
 tp=(1,2,3,4,5,6,7,8,9,10)
 li=list()
 for i in tp:
@@ -1101,151 +1009,121 @@ for i in tp:
 
 tp2=tuple(li)
 print tp2
-
-
-
-#----------------------------------------#
-2.14
-
-Question:
+```
+ #### Question:
 Write a program which accepts a string as input to print "Yes" if the string is "yes" or "YES" or "Yes", otherwise print "No". 
 
-Hints:
+**Hints:**
 
 Use if statement to judge condition.
 
-Solution
+**Solution:** 
+``` python
 s= raw_input()
 if s=="yes" or s=="YES" or s=="Yes":
     print "Yes"
 else:
     print "No"
-
-
-
-#----------------------------------------#
-3.4
-
-Question:
+``` 
+#### Question:
 Write a program which can filter even numbers in a list by using filter function. The list is: [1,2,3,4,5,6,7,8,9,10].
 
-Hints:
+**Hints:**
 
 Use filter() to filter some elements in a list.
 Use lambda to define anonymous functions.
 
-Solution
+**Solution:** 
+``` python
 li = [1,2,3,4,5,6,7,8,9,10]
 evenNumbers = filter(lambda x: x%2==0, li)
 print evenNumbers
+``` 
 
-
-#----------------------------------------#
-3.4
-
-Question:
+#### Question:
 Write a program which can map() to make a list whose elements are square of elements in [1,2,3,4,5,6,7,8,9,10].
 
-Hints:
+**Hints:**
 
 Use map() to generate a list.
 Use lambda to define anonymous functions.
 
-Solution
+**Solution:**
+``` python
 li = [1,2,3,4,5,6,7,8,9,10]
 squaredNumbers = map(lambda x: x**2, li)
 print squaredNumbers
+``` 
 
-#----------------------------------------#
-3.5
-
-Question:
+#### Question:
 Write a program which can map() and filter() to make a list whose elements are square of even number in [1,2,3,4,5,6,7,8,9,10].
 
-Hints:
+**Hints:**
 
 Use map() to generate a list.
 Use filter() to filter elements of a list.
 Use lambda to define anonymous functions.
 
-Solution
+**Solution:** 
+``` python
 li = [1,2,3,4,5,6,7,8,9,10]
 evenNumbers = map(lambda x: x**2, filter(lambda x: x%2==0, li))
 print evenNumbers
+``` 
 
-
-
-
-#----------------------------------------#
-3.5
-
-Question:
+#### Question:
 Write a program which can filter() to make a list whose elements are even number between 1 and 20 (both included).
 
-Hints:
+**Hints:**
 
 Use filter() to filter elements of a list.
 Use lambda to define anonymous functions.
 
-Solution
+**Solution:** 
+``` python
 evenNumbers = filter(lambda x: x%2==0, range(1,21))
 print evenNumbers
-
-
-#----------------------------------------#
-3.5
-
-Question:
+``` 
+#### Question:
 Write a program which can map() to make a list whose elements are square of numbers between 1 and 20 (both included).
 
-Hints:
+**Hints:**
 
 Use map() to generate a list.
 Use lambda to define anonymous functions.
 
-Solution
+**Solution:** 
+``` python
 squaredNumbers = map(lambda x: x**2, range(1,21))
 print squaredNumbers
-
-
-
-
-#----------------------------------------#
-7.2
-
-Question:
+```
+#### Question:
 Define a class named American which has a static method called printNationality.
 
-Hints:
+**Hints:**
 
 Use @staticmethod decorator to define class static method.
 
-Solution
+**Solution:** 
+``` python
 class American(object):
     @staticmethod
     def printNationality():
-        print "America"
-
-anAmerican = American()
-anAmerican.printNationality()
-American.printNationality()
-
-
-
-
-#----------------------------------------#
-
-7.2
+        print "America"
 
-Question:
+anAmerican = American()
+anAmerican.printNationality()
+American.printNationality()
+``` 
+#### Question:
 Define a class named American and its subclass NewYorker. 
 
-Hints:
+**Hints:**
 
 Use class Subclass(ParentClass) to define a subclass.
 
-Solution:
-
+**Solution:** 
+``` python
 class American(object):
     pass
 
@@ -1256,24 +1134,17 @@ anAmerican = American()
 aNewYorker = NewYorker()
 print anAmerican
 print aNewYorker
+``` 
 
-
-
-
-#----------------------------------------#
-
-
-7.2
-
-Question:
+#### Question:
 Define a class named Circle which can be constructed by a radius. The Circle class has a method which can compute the area. 
 
-Hints:
+**Hints:**
 
 Use def methodName(self) to define a method.
 
-Solution:
-
+**Solution:**
+``` python
 class Circle(object):
     def __init__(self, r):
         self.radius = r
@@ -1283,24 +1154,16 @@ class Circle(object):
 
 aCircle = Circle(2)
 print aCircle.area()
-
-
-
-
-
-
-#----------------------------------------#
-
-7.2
-
+```
+#### Question:
 Define a class named Rectangle which can be constructed by a length and width. The Rectangle class has a method which can compute the area. 
 
-Hints:
+**Hints:**
 
 Use def methodName(self) to define a method.
 
-Solution:
-
+**Solution:** 
+``` python
 class Rectangle(object):
     def __init__(self, l, w):
         self.length = l
@@ -1311,21 +1174,16 @@ class Rectangle(object):
 
 aRectangle = Rectangle(2,10)
 print aRectangle.area()
-
-
-
-
-#----------------------------------------#
-
-7.2
-
+```
+#### Question:
 Define a class named Shape and its subclass Square. The Square class has an init function which takes a length as argument. Both classes have a area function which can print the area of the shape where Shape's area is 0 by default.
 
-Hints:
+**Hints:**
 
 To override a method in super class, we can define a method with the same name in the super class.
 
-Solution:
+**Solution:**
+``` python
 
 class Shape(object):
     def __init__(self):
@@ -1344,38 +1202,29 @@ class Square(Shape):
 
 aSquare= Square(3)
 print aSquare.area()
-
-
-
-
-
-
-
-
-#----------------------------------------#
-
+```
+#### Question:
 
 Please raise a RuntimeError exception.
 
-Hints:
+**Hints:**
 
 Use raise() to raise an exception.
 
-Solution:
-
+**Solution:** 
+``` python
 raise RuntimeError('something wrong')
+```
+ #### Question:
 
-
-
-#----------------------------------------#
 Write a function to compute 5/0 and use try/except to catch the exceptions.
 
-Hints:
+**Hints:**
 
 Use try/except to catch exceptions.
 
-Solution:
-
+**Solution:** 
+``` python
 def throws():
     return 5/0
 
@@ -1387,16 +1236,17 @@ except Exception, err:
     print 'Caught an exception'
 finally:
     print 'In finally block for cleanup'
+``` 
+#### Question:
 
-
-#----------------------------------------#
 Define a custom exception class which takes a string message as attribute.
 
-Hints:
+**Hints:**
 
 To define a custom exception, we need to define a class inherited from Exception.
 
-Solution:
+**Solution:** 
+``` python
 
 class MyError(Exception):
     """My own exception class
@@ -1409,9 +1259,8 @@ class MyError(Exception):
         self.msg = msg
 
 error = MyError("something wrong")
-
-#----------------------------------------#
-Question:
+``` 
+#### Question:
 
 Assuming that we have some email addresses in the "username@companyname.com" format, please write program to print the user name of a given email address. Both user names and company names are composed of letters only.
 
@@ -1426,20 +1275,19 @@ john
 
 In case of input data being supplied to the question, it should be assumed to be a console input.
 
-Hints:
+**Hints:**
 
 Use \w to match letters.
 
-Solution:
+**Solution:** 
+``` python
 import re
 emailAddress = raw_input()
 pat2 = "(\w+)@((\w+\.)+(com))"
 r2 = re.match(pat2,emailAddress)
 print r2.group(1)
-
-
-#----------------------------------------#
-Question:
+``` 
+#### Question:
 
 Assuming that we have some email addresses in the "username@companyname.com" format, please write program to print the company name of a given email address. Both user names and company names are composed of letters only.
 
@@ -1454,22 +1302,19 @@ google
 
 In case of input data being supplied to the question, it should be assumed to be a console input.
 
-Hints:
+**Hints:**
 
 Use \w to match letters.
 
-Solution:
+**Solution:** 
+``` python
 import re
 emailAddress = raw_input()
 pat2 = "(\w+)@(\w+)\.(com)"
 r2 = re.match(pat2,emailAddress)
 print r2.group(2)
-
-
-
-
-#----------------------------------------#
-Question:
+``` 
+#### Question:
 
 Write a program which accepts a sequence of words separated by whitespace as input to print the words composed of digits only.
 
@@ -1484,57 +1329,60 @@ Then, the output of the program should be:
 
 In case of input data being supplied to the question, it should be assumed to be a console input.
 
-Hints:
+**Hints:**
 
 Use re.findall() to find all substring using regex.
 
-Solution:
+**Solution:** 
+``` python
 import re
 s = raw_input()
 print re.findall("\d+",s)
+``` 
 
-
-#----------------------------------------#
-Question:
-
+#### Question:
 
 Print a unicode string "hello world".
 
-Hints:
+**Hints:**
 
 Use u'strings' format to define unicode string.
 
-Solution:
-
+**Solution:** 
+``` python
 unicodeString = u"hello world!"
 print unicodeString
+```
 
-#----------------------------------------#
+
+#### Question:
 Write a program to read an ASCII string and to convert it to a unicode string encoded by utf-8.
 
-Hints:
+**Hints:**
 
 Use unicode() function to convert.
 
-Solution:
+**Solution:** 
+
+``` python
 
 s = raw_input()
 u = unicode( s ,"utf-8")
 print u
 
-#----------------------------------------#
-Question:
+``` 
+#### Question:
 
 Write a special comment to indicate a Python source code file is in unicode.
 
-Hints:
+**Hints:**
 
-Solution:
+**Solution:** 
 
+``` python
 # -*- coding: utf-8 -*-
-
-#----------------------------------------#
-Question:
+```
+#### Question:
 
 Write a program to compute 1/2+2/3+3/4+...+n/n+1 with a given n input by console (n>0).
 
@@ -1549,20 +1397,20 @@ Then, the output of the program should be:
 
 In case of input data being supplied to the question, it should be assumed to be a console input.
 
-Hints:
+**Hints:**
 Use float() to convert an integer to a float
 
-Solution:
+**Solution:** 
 
+``` python
 n=int(raw_input())
 sum=0.0
 for i in range(1,n+1):
     sum += float(float(i)/(i+1))
 print sum
+```
 
-
-#----------------------------------------#
-Question:
+#### Question:
 
 Write a program to compute:
 
@@ -1582,11 +1430,12 @@ Then, the output of the program should be:
 
 In case of input data being supplied to the question, it should be assumed to be a console input.
 
-Hints:
+**Hints:**
 We can define recursive function in Python.
 
-Solution:
+**Solution:** 
 
+``` python
 def f(n):
     if n==0:
         return 0
@@ -1595,11 +1444,9 @@ def f(n):
 
 n=int(raw_input())
 print f(n)
+```
 
-#----------------------------------------#
-
-Question:
-
+#### Question:
 
 The Fibonacci Sequence is computed based on the following formula:
 
@@ -1621,12 +1468,13 @@ Then, the output of the program should be:
 
 In case of input data being supplied to the question, it should be assumed to be a console input.
 
-Hints:
+**Hints:**
 We can define recursive function in Python.
 
 
-Solution:
+**Solution:** 
 
+``` python
 def f(n):
     if n == 0: return 0
     elif n == 1: return 1
@@ -1634,13 +1482,8 @@ def f(n):
 
 n=int(raw_input())
 print f(n)
-
-
-#----------------------------------------#
-
-#----------------------------------------#
-
-Question:
+```
+#### Question:
 
 The Fibonacci Sequence is computed based on the following formula:
 
@@ -1661,15 +1504,16 @@ Then, the output of the program should be:
 0,1,1,2,3,5,8,13
 
 
-Hints:
+**Hints:**
 We can define recursive function in Python.
 Use list comprehension to generate a list from an existing list.
 Use string.join() to join a list of strings.
 
 In case of input data being supplied to the question, it should be assumed to be a console input.
 
-Solution:
+**Solution:** 
 
+``` python
 def f(n):
     if n == 0: return 0
     elif n == 1: return 1
@@ -1678,11 +1522,8 @@ def f(n):
 n=int(raw_input())
 values = [str(f(x)) for x in range(0, n+1)]
 print ",".join(values)
-
-
-#----------------------------------------#
-
-Question:
+```
+#### Question:
 
 Please write a program using generator to print the even numbers between 0 and n in comma separated form while n is input by console.
 
@@ -1695,13 +1536,13 @@ Then, the output of the program should be:
 
 0,2,4,6,8,10
 
-Hints:
+**Hints:**
 Use yield to produce the next value in generator.
 
 In case of input data being supplied to the question, it should be assumed to be a console input.
 
-Solution:
-
+**Solution:** 
+``` python
 def EvenGenerator(n):
     i=0
     while i<=n:
@@ -1716,11 +1557,8 @@ for i in EvenGenerator(n):
     values.append(str(i))
 
 print ",".join(values)
-
-
-#----------------------------------------#
-
-Question:
+```
+ #### Question:
 
 Please write a program using generator to print the numbers which can be divisible by 5 and 7 between 0 and n in comma separated form while n is input by console.
 
@@ -1733,13 +1571,13 @@ Then, the output of the program should be:
 
 0,35,70
 
-Hints:
+**Hints:**
 Use yield to produce the next value in generator.
 
 In case of input data being supplied to the question, it should be assumed to be a console input.
 
-Solution:
-
+**Solution:**
+``` python
 def NumGenerator(n):
     for i in range(n+1):
         if i%5==0 and i%7==0:
@@ -1751,31 +1589,25 @@ for i in NumGenerator(n):
     values.append(str(i))
 
 print ",".join(values)
-
-
-#----------------------------------------#
-
-Question:
-
+```
+ #### Question:
 
 Please write assert statements to verify that every number in the list [2,4,6,8] is even.
 
 
 
-Hints:
+**Hints:**
 Use "assert expression" to make assertion.
 
 
-Solution:
-
+**Solution:** 
+``` python
 li = [2,4,6,8]
 for i in li:
     assert i%2==0
+``` 
 
-
-#----------------------------------------#
-Question:
-
+#### Question:
 Please write a program which accepts basic mathematic expression from console and print the evaluation result.
 
 Example:
@@ -1787,28 +1619,26 @@ Then, the output of the program should be:
 
 38
 
-Hints:
+**Hints:**
 Use eval() to evaluate an expression.
 
 
-Solution:
-
+**Solution:** 
+``` python
 expression = raw_input()
 print eval(expression)
-
-
-#----------------------------------------#
-Question:
+```
+#### Question:
 
 Please write a binary search function which searches an item in a sorted list. The function should return the index of element to be searched in the list.
 
 
-Hints:
+**Hints:**
 Use if/elif to deal with conditions.
 
 
-Solution:
-
+**Solution:** 
+``` python
 import math
 def bin_search(li, element):
     bottom = 0
@@ -1828,22 +1658,18 @@ def bin_search(li, element):
 li=[2,5,7,9,11,17,222]
 print bin_search(li,11)
 print bin_search(li,12)
-
-
-
-
-#----------------------------------------#
-Question:
+``` 
+#### Question:
 
 Please write a binary search function which searches an item in a sorted list. The function should return the index of element to be searched in the list.
 
 
-Hints:
+**Hints:**
 Use if/elif to deal with conditions.
 
 
-Solution:
-
+**Solution:** 
+``` python
 import math
 def bin_search(li, element):
     bottom = 0
@@ -1863,226 +1689,199 @@ def bin_search(li, element):
 li=[2,5,7,9,11,17,222]
 print bin_search(li,11)
 print bin_search(li,12)
-
-
-
-
-#----------------------------------------#
-Question:
+``` 
+#### Question:
 
 Please generate a random float where the value is between 10 and 100 using Python math module.
 
 
 
-Hints:
+**Hints:**
 Use random.random() to generate a random float in [0,1].
 
 
-Solution:
-
+**Solution:** 
+``` python
 import random
 print random.random()*100
+```
 
-#----------------------------------------#
-Question:
-
+#### Question:
 Please generate a random float where the value is between 5 and 95 using Python math module.
 
 
 
-Hints:
+**Hints:**
 Use random.random() to generate a random float in [0,1].
 
-
-Solution:
-
+**Solution:** 
+``` python
 import random
 print random.random()*100-5
-
-
-#----------------------------------------#
-Question:
+``` 
+#### Question:
 
 Please write a program to output a random even number between 0 and 10 inclusive using random module and list comprehension.
 
 
-
-Hints:
+**Hints:**
 Use random.choice() to a random element from a list.
 
-
-Solution:
-
+**Solution:**
+``` python
 import random
 print random.choice([i for i in range(11) if i%2==0])
-
-
-#----------------------------------------#
-Question:
+``` 
+#### Question:
 
 Please write a program to output a random number, which is divisible by 5 and 7, between 0 and 10 inclusive using random module and list comprehension.
 
 
 
-Hints:
+**Hints:**
 Use random.choice() to a random element from a list.
 
 
-Solution:
-
+**Solution:** 
+``` python
 import random
 print random.choice([i for i in range(201) if i%5==0 and i%7==0])
+```
 
-
-
-#----------------------------------------#
-
-Question:
+#### Question:
 
 Please write a program to generate a list with 5 random numbers between 100 and 200 inclusive.
 
 
 
-Hints:
+**Hints:**
 Use random.sample() to generate a list of random values.
 
 
-Solution:
+**Solution:** 
 
+``` python
 import random
 print random.sample(range(100), 5)
-
-#----------------------------------------#
-Question:
+```
+ #### Question:
 
 Please write a program to randomly generate a list with 5 even numbers between 100 and 200 inclusive.
 
 
 
-Hints:
+**Hints:**
 Use random.sample() to generate a list of random values.
 
 
-Solution:
-
+**Solution:** 
+``` python
 import random
 print random.sample([i for i in range(100,201) if i%2==0], 5)
-
-
-#----------------------------------------#
-Question:
+``` 
+#### Question:
 
 Please write a program to randomly generate a list with 5 numbers, which are divisible by 5 and 7 , between 1 and 1000 inclusive.
 
 
 
-Hints:
+**Hints:**
 Use random.sample() to generate a list of random values.
 
 
-Solution:
-
+**Solution:** 
+``` python
 import random
 print random.sample([i for i in range(1,1001) if i%5==0 and i%7==0], 5)
-
-#----------------------------------------#
-
-Question:
+``` 
+#### Question:
 
 Please write a program to randomly print a integer number between 7 and 15 inclusive.
 
 
 
-Hints:
+**Hints:**
 Use random.randrange() to a random integer in a given range.
 
 
-Solution:
-
+**Solution:** 
+``` python
 import random
 print random.randrange(7,16)
-
-#----------------------------------------#
-
-Question:
+```
+ #### Question:
 
 Please write a program to compress and decompress the string "hello world!hello world!hello world!hello world!".
 
 
 
-Hints:
+**Hints:**
 Use zlib.compress() and zlib.decompress() to compress and decompress a string.
 
 
-Solution:
-
+**Solution:**
+``` python
 import zlib
 s = 'hello world!hello world!hello world!hello world!'
 t = zlib.compress(s)
 print t
 print zlib.decompress(t)
-
-#----------------------------------------#
-Question:
+```
+#### Question:
 
 Please write a program to print the running time of execution of "1+1" for 100 times.
 
 
 
-Hints:
+**Hints:**
 Use timeit() function to measure the running time.
 
-Solution:
-
+**Solution:**
+``` python
 from timeit import Timer
 t = Timer("for i in range(100):1+1")
 print t.timeit()
-
-#----------------------------------------#
-Question:
+``` 
+#### Question:
 
 Please write a program to shuffle and print the list [3,6,7,8].
 
 
-
-Hints:
+**Hints:**
 Use shuffle() function to shuffle a list.
 
-Solution:
-
+**Solution:** 
+``` python
 from random import shuffle
 li = [3,6,7,8]
 shuffle(li)
 print li
-
-#----------------------------------------#
-Question:
+``` 
+#### Question:
 
 Please write a program to shuffle and print the list [3,6,7,8].
 
 
 
-Hints:
+**Hints:**
 Use shuffle() function to shuffle a list.
 
-Solution:
-
+**Solution:** 
+``` python
 from random import shuffle
 li = [3,6,7,8]
 shuffle(li)
 print li
-
-
-
-#----------------------------------------#
-Question:
+``` 
+#### Question:
 
 Please write a program to generate all sentences where subject is in ["I", "You"] and verb is in ["Play", "Love"] and the object is in ["Hockey","Football"].
 
-Hints:
+**Hints:**
 Use list[index] notation to get a element from a list.
 
-Solution:
+**Solution:** 
+``` python
 
 subjects=["I", "You"]
 verbs=["Play", "Love"]
@@ -2092,122 +1891,112 @@ for i in range(len(subjects)):
         for k in range(len(objects)):
             sentence = "%s %s %s." % (subjects[i], verbs[j], objects[k])
             print sentence
+```
 
+#### Question:
+Please write a program to print the list after removing delete even numbers in `[5, 6, 77, 45, 22, 12, 24]`.
 
-#----------------------------------------#
-Please write a program to print the list after removing delete even numbers in [5,6,77,45,22,12,24].
-
-Hints:
+**Hints:**
 Use list comprehension to delete a bunch of element from a list.
 
-Solution:
-
+**Solution:** 
+``` python
 li = [5,6,77,45,22,12,24]
 li = [x for x in li if x%2!=0]
 print li
-
-#----------------------------------------#
-Question:
+``` 
+#### Question:
 
 By using list comprehension, please write a program to print the list after removing delete numbers which are divisible by 5 and 7 in [12,24,35,70,88,120,155].
 
-Hints:
+**Hints:**
 Use list comprehension to delete a bunch of element from a list.
 
-Solution:
-
+**Solution:** 
+``` python
 li = [12,24,35,70,88,120,155]
 li = [x for x in li if x%5!=0 and x%7!=0]
 print li
-
-
-#----------------------------------------#
-Question:
+```
+#### Question:
 
 By using list comprehension, please write a program to print the list after removing the 0th, 2nd, 4th,6th numbers in [12,24,35,70,88,120,155].
 
-Hints:
+**Hints:**
 Use list comprehension to delete a bunch of element from a list.
 Use enumerate() to get (index, value) tuple.
 
-Solution:
-
+**Solution:** 
+``` python
 li = [12,24,35,70,88,120,155]
 li = [x for (i,x) in enumerate(li) if i%2!=0]
 print li
-
-#----------------------------------------#
-
-Question:
+```
+#### Question:
 
 By using list comprehension, please write a program generate a 3*5*8 3D array whose each element is 0.
 
-Hints:
+**Hints:**
 Use list comprehension to make an array.
 
-Solution:
-
+**Solution:**
+``` python
 array = [[ [0 for col in range(8)] for col in range(5)] for row in range(3)]
 print array
-
-#----------------------------------------#
-Question:
+```
+#### Question:
 
 By using list comprehension, please write a program to print the list after removing the 0th,4th,5th numbers in [12,24,35,70,88,120,155].
 
-Hints:
+**Hints:**
 Use list comprehension to delete a bunch of element from a list.
 Use enumerate() to get (index, value) tuple.
 
-Solution:
-
+**Solution:** 
+``` python
 li = [12,24,35,70,88,120,155]
 li = [x for (i,x) in enumerate(li) if i not in (0,4,5)]
 print li
-
-
-
-#----------------------------------------#
-
-Question:
+``` 
+#### Question:
 
 By using list comprehension, please write a program to print the list after removing the value 24 in [12,24,35,24,88,120,155].
 
-Hints:
+**Hints:**
 Use list's remove method to delete a value.
 
-Solution:
+**Solution:** 
+``` python
 
 li = [12,24,35,24,88,120,155]
 li = [x for x in li if x!=24]
 print li
-
-
-#----------------------------------------#
-Question:
+```
+#### Question:
 
 With two given lists [1,3,6,78,35,55] and [12,24,35,24,88,120,155], write a program to make a list whose elements are intersection of the above given lists.
 
-Hints:
+**Hints:**
 Use set() and "&=" to do set intersection operation.
 
-Solution:
-
+**Solution:** 
+``` python
 set1=set([1,3,6,78,35,55])
 set2=set([12,24,35,24,88,120,155])
 set1 &= set2
 li=list(set1)
 print li
+```
 
-#----------------------------------------#
+#### Question:
 
 With a given list [12,24,35,24,88,120,155,88,120,155], write a program to print this list after removing all duplicate values with original order reserved.
 
-Hints:
+**Hints:**
 Use set() to store a number of values without duplicate.
 
-Solution:
-
+**Solution:** 
+``` python
 def removeDuplicate( li ):
     newli=[]
     seen = set()
@@ -2220,18 +2009,16 @@ def removeDuplicate( li ):
 
 li=[12,24,35,24,88,120,155,88,120,155]
 print removeDuplicate(li)
+```
 
-
-#----------------------------------------#
-Question:
-
+ #### Question:
 Define a class Person and its two child classes: Male and Female. All classes have a method "getGender" which can print "Male" for Male class and "Female" for Female class.
 
-Hints:
+**Hints:**
 Use Subclass(Parentclass) to define a child class.
 
-Solution:
-
+**Solution:**
+``` python
 class Person(object):
     def getGender( self ):
         return "Unknown"
@@ -2248,11 +2035,8 @@ aMale = Male()
 aFemale= Female()
 print aMale.getGender()
 print aFemale.getGender()
-
-
-
-#----------------------------------------#
-Question:
+```
+#### Question:
 
 Please write a program which count and print the numbers of each character in a string input by console.
 
@@ -2271,22 +2055,19 @@ d,1
 g,1
 f,1
 
-Hints:
+**Hints:**
 Use dict to store key/value pairs.
 Use dict.get() method to lookup a key with default value.
 
-Solution:
-
+**Solution:** 
+``` python
 dic = {}
 s=raw_input()
 for s in s:
     dic[s] = dic.get(s,0)+1
 print '\n'.join(['%s,%s' % (k, v) for k, v in dic.items()])
-
-#----------------------------------------#
-
-Question:
-
+```
+ #### Question:
 Please write a program which accepts a string from console and print it in reverse order.
 
 Example:
@@ -2298,18 +2079,16 @@ Then, the output of the program should be:
 
 ris etov ot esir
 
-Hints:
+**Hints:**
 Use list[::-1] to iterate a list in a reverse order.
 
-Solution:
-
+**Solution:** 
+``` python
 s=raw_input()
 s = s[::-1]
 print s
-
-#----------------------------------------#
-
-Question:
+```
+#### Question:
 
 Please write a program which accepts a string from console and print the characters that have even indexes.
 
@@ -2322,32 +2101,29 @@ Then, the output of the program should be:
 
 Helloworld
 
-Hints:
+**Hints:**
 Use list[::2] to iterate a list by step 2.
 
-Solution:
-
+**Solution:** 
+``` python
 s=raw_input()
 s = s[::2]
 print s
-#----------------------------------------#
-
-
-Question:
+```
+#### Question:
 
 Please write a program which prints all permutations of [1,2,3]
 
 
-Hints:
+**Hints:**
 Use itertools.permutations() to get permutations of list.
 
-Solution:
-
+**Solution:**
+``` python
 import itertools
 print list(itertools.permutations([1,2,3]))
-
-#----------------------------------------#
-Question:
+``` 
+#### Question:
 
 Write a program to solve a classic ancient Chinese puzzle: 
 We count 35 heads and 94 legs among the chickens and rabbits in a farm. How many rabbits and how many chickens do we have?
@@ -2355,8 +2131,8 @@ We count 35 heads and 94 legs among the chickens and rabbits in a farm. How many
 Hint:
 Use for loop to iterate all possible solutions.
 
-Solution:
-
+**Solution:**
+``` python
 def solve(numheads,numlegs):
     ns='No solutions!'
     for i in range(numheads+1):
@@ -2369,7 +2145,6 @@ numheads=35
 numlegs=94
 solutions=solve(numheads,numlegs)
 print solutions
-
-#----------------------------------------#
+```