three leetcode problems

Author: springuper

largestNumber.py

@@ -0,0 +1,21 @@
+# @param num, a list of integers
+# @return a string
+def largestNumber(num):
+        def strSort(x, y):
+            x = str(x)
+            y = str(y)
+            return 1 if (x + y) > (y + x) else -1
+
+        l = sorted(num, cmp=strSort, reverse=True)
+        print l
+        if l[0] == 0:
+            return '0';
+        ret = ''
+        for i in l:
+            ret += str(i)
+        return ret
+
+assert largestNumber([0, 0]) == '0'
+assert largestNumber([3, 30, 34, 5, 9]) == '9534330'
+assert largestNumber([824,938,1399,5607,6973,5703,9609,4398,8247]) == '9609938824824769735703560743981399'
+assert largestNumber([9051,5526,2264,5041,1630,5906,6787,8382,4662,4532,6804,4710,4542,2116,7219,8701,8308,957,8775,4822,396,8995,8597,2304,8902,830,8591,5828,9642,7100,3976,5565,5490,1613,5731,8052,8985,2623,6325,3723,5224,8274,4787,6310,3393,78,3288,7584,7440,5752,351,4555,7265,9959,3866,9854,2709,5817,7272,43,1014,7527,3946,4289,1272,5213,710,1603,2436,8823,5228,2581,771,3700,2109,5638,3402,3910,871,5441,6861,9556,1089,4088,2788,9632,6822,6145,5137,236,683,2869,9525,8161,8374,2439,6028,7813,6406,7519]) == '995998549642963295795569525905189958985890288238775871870185978591838283748308830827481618052787813771758475277519744072727265721971071006861683682268046787640663256310614560285906582858175752573156385565552654905441522852245213513750414822478747104662455545424532434289408839763963946391038663723370035134023393328828692788270926232581243924362362304226421162109163016131603127210891014'

subsets.py

@@ -0,0 +1,20 @@
+# @param S, a list of integer
+# @return a list of lists of integer
+def subsets(S):
+    ret = []
+    length = len(S)
+    # sort
+    S.sort()
+
+    # traverse
+    def traverse(s, level):
+        if level == length:
+            ret.append(s)
+            return
+        traverse(s, level + 1)
+        traverse(s + [S[level]], level + 1)
+
+    traverse([], 0)
+    return ret;
+
+assert subsets([1, 2, 3]) == [[], [3], [2], [2, 3], [1], [1, 3], [1, 2], [1, 2, 3]]

subsetsWithDup.py

@@ -0,0 +1,21 @@
+# @param S, a list of integer
+# @return a list of lists of integer
+def subsets(S):
+        ret = []
+        length = len(S)
+        # sort
+        S.sort()
+
+        # traverse
+        def traverse(s, level, flag):
+            if level == length:
+                ret.append(s)
+                return
+            traverse(s + [S[level]], level + 1, True)
+            if level == 0 or S[level] != S[level - 1] or not flag:
+                traverse(s, level + 1, False)
+
+        traverse([], 0, False)
+        return ret;
+
+assert subsets([1, 2, 2]) == [[1, 2, 2], [1, 2], [1], [2, 2], [2], []]