leetcode 第五题 Longest Palindromic Substring （java）

Longest Palindromic Substring

Given a string S, find the longest palindromic substring in S. You may assume that the maximum length of S is 1000, and there exists one unique longest palindromic substring.

time=255ms    accepted 暴力遍历

public String longestPalindrome(String s){String result=null;int length=s.length();int max=0;if(length==0)return null;else if(length==1)return s;else{for(int i=1;i<length;i++){       boolean b=false;int k=0;int j=0;for(int m=i-1;m>=0&&m>=i-2;m--){if(s.charAt(i)==s.charAt(m)){k=m-1;b=true;j=i+1;while(b&&k>=0&&j<length){                    	if(s.charAt(j)==s.charAt(k)){j++;k--;}elseb=false;}	                   if(max<j-k-1){result=s.substring(k+1,j);max=j-k-1;}}}if(j>=length)break;}return result;}}