refs #leetcode - some problems

Author: YugenCoder

AddTwoNumbers.java

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+package leetcode;
+
+public class AddTwoNumbers {
+
+	public static void main(String[] args) {
+		ListNode l1 = new ListNode(2);
+		l1.next = new ListNode(4);
+		l1.next.next = new  ListNode(3);
+
+		ListNode l2 = new ListNode(5);
+		l1.next = new ListNode(6);
+		l1.next.next = new  ListNode(4);
+		AddTwoNumbers solution = new AddTwoNumbers();
+		ListNode l3 = solution.addTwoNumbers(l1,l2);
+		//[2,4,3]
+//[5,6,4]
+
+	}
+	public ListNode addTwoNumbers(ListNode l1, ListNode l2) {
+        
+        return makeList(l1,l2);
+   
+   }
+
+    ListNode makeList(ListNode l1, ListNode l2){
+        ListNode ln = new ListNode(0);
+        ListNode ret = ln;
+        int carry = 0,num1,num2,sum;
+        while((l1!= null) || (l2!=null)){
+            num1 = (l1!=null)?l1.val:0;
+            num2 = (l2!=null)?l2.val:0;
+            sum = num1 + num2 + carry;
+            carry = (sum >= 10)?1:0;
+            ln.next = new ListNode(sum%10);
+ 
+            if(l1 !=null ){
+                l1 = l1.next;
+            }
+            if(l2 !=null ){
+                l2 = l2.next;
+            }
+            ln = ln.next;
+        }
+        if(carry > 0){
+            ln.next = new ListNode(carry);
+        }
+        return ret.next;
+    }
+   
+
+}

FindMedianSortedArrays.java

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+package leetcode;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
+
+public class FindMedianSortedArrays {
+	public static void main(String[] args) {
+		// TestCases
+		FindMedianSortedArrays fmsa = new FindMedianSortedArrays();
+		int[] result = new int[3];
+		//List<String> testcases = new ArrayList();
+		//testcases = Arrays.asList("abcabcbb", "bbbbb", "pwwkew","abba");
+		int[][] testcases = {{50,60,55,67},{62,65,70,70}};
+			System.out.println(fmsa.findMedianSortedArrays(testcases[0],testcases[1])+"\n");
+	}
+    public double findMedianSortedArrays(int[] nums1, int[] nums2) {
+    	int len1 = nums1.length;
+    	int len2 = nums2.length;
+    	int res1 = 0,res2 = 0,mid1,mid2;
+    	//Odd Case
+    	
+    	//Even Case
+    	
+    	
+		return 0;
+        
+    }
+
+
+}

LengthOfLongestSubstring.java

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+package leetcode;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+
+public class LengthOfLongestSubstring {
+	public static void main(String[] args) {
+		// TestCases
+		LengthOfLongestSubstring lls = new LengthOfLongestSubstring();
+		int[] result = new int[3];
+		List<String> testcases = new ArrayList();
+		testcases = Arrays.asList("abcabcbb", "bbbbb", "pwwkew","abba");
+		
+		for(String testcase:testcases) {
+			System.out.println(lls.lengthOfLongestSubstring(testcase)+"\n");
+		}
+	}
+
+	public int lengthOfLongestSubstring(String s) {
+		int start = 0, end = 0;
+		int result = 0;
+		Map<Character,Integer> history = new HashMap<>();
+		for (int i = 0; i < s.length(); i++) {
+			if(history.containsKey(s.charAt(i))) {
+				start = Math.max(history.get(s.charAt(i))+1,start);
+			}
+			result = (result < (end - start + 1))?(end - start + 1):result;
+			history.put(s.charAt(i), i);
+			end++;
+		}
+		return result;
+	}
+}

LongestPalindrome.java

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+package leetcode;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
+
+public class LongestPalindrome {
+	public static void main(String[] args) {
+		// TestCases
+		LongestPalindrome lls = new LongestPalindrome();
+		int[] result = new int[3];
+		List<String> testcases = new ArrayList();
+		testcases = Arrays.asList("satas", "garbage", "somethingada","abba");
+		
+		for(String testcase:testcases) {
+			System.out.println(lls.longestPalindrome(testcase)+"\n");
+		}
+	}
+    public String longestPalindrome(String s) {
+    	
+    	//memory
+    	int [][]mem = new int[s.length()][s.length()];
+    	int maxLen = 1;
+    	int idx = 0;
+    	// initialize
+    	for (int i=0;i<s.length();i++) {
+    		mem[i][i] = 1;
+    	}
+    	for (int i=0;i<s.length()-1;i++) {
+    		if(s.charAt(i) == s.charAt(i+1)) {
+    			mem[i][i+1] = 1;
+
+				if(maxLen < 2) {
+	    			idx = i;
+	    			maxLen = 2;
+    			}
+    		}
+    	}
+    	for (int i1=2;i1<s.length();i1++) {
+    		for (int j = 0; j < s.length() - i1 ; j++) {
+    			if(s.charAt(j) == s.charAt(j+i1) && mem[j+1][j+i1-1] > 0) {
+    				mem[j][j+i1] = 1 + mem[j+1][j+i1-1];
+    				if(maxLen < i1+1) {
+    					maxLen = i1 + 1;
+    					idx = j;
+        			}
+    			}
+			}
+    	}
+		return s.substring(idx, idx+maxLen);
+        
+    }
+}

ZigZagConversion.java

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+package leetcode;
+
+	import java.util.Arrays;
+import java.util.List;
+
+	public class ZigZagConversion {
+		public static void main(String[] args) {
+			// TestCases
+			ZigZagConversion lls = new ZigZagConversion();
+			int[] result = new int[3];
+			String res = convert("PAYPALISHIRING",3);
+			System.out.println(res);
+		}
+	    public static String convert(String s, int numRows) {
+	    	StringBuffer[] str = new StringBuffer[numRows];
+	    	for (int i = 0; i < numRows; i++) {	
+	    		str[i] = new StringBuffer();	
+			}
+	    	StringBuffer res = new StringBuffer();
+	    	
+	    	//
+	    	int idx = 0;
+	    	
+	    	while(idx < s.length()) {
+	    		//going down
+	    		for (int i = 0; i < numRows && idx < s.length(); i++,idx++) {	
+	    			str[i].append(s.charAt(idx));
+	    		}
+	    		for (int i = numRows-2; i > 0 && idx < s.length(); i--,idx++) {	
+	    			str[i].append(s.charAt(idx));
+	    		}
+	    	}
+	    	
+	    	//Join to get result
+	    	for (int i = 0; i < numRows; i++) {
+	    		res.append(str[i]);
+			}
+			return res.toString();
+	        
+	    }
+	}