[Leetcode] [Java] Longest palindromic Substring

Topic:

Given A stringS, find the longest palindromic substring inS. Assume that maximum length ofSis, and there exists one unique longest palindromic substring.

Test instructions

Given the string s, locate the longest palindrome substring in the string. Assume that the maximum length of this substring is 1000, and that the longest palindrome string is present and unique.

Algorithm Analysis:

The palindrome string is symmetrical in the center axis, so if we start with subscript I, we use 2 pointers to expand the two sides of I to determine whether it is equal
Note that the string of characters has odd-even symmetry

The code is as follows:

    Public String Longestpalindrome (string s)     {if (s==null| | S.length () <=1) return s; String maxres= ""; String res= "";    for (int i=0;i<s.length (); i++) {res=getnum (s,i,i);//palindrome string with I as Center if (maxres.length () <res.length ()) maxres=res;res= Getnum (s,i,i+1);//palindrome string with i,i+1 as the center if (maxres.length () <res.length ()) Maxres=res;} return maxres;    } private static string Getnum (string s, int begin,int end) {while (Begin>=0&&end<=s.length ()-1) {if ( S.charat (BEGIN) ==s.charat (end) {begin--;end++;} else break;} Return s.substring (begin+1,end);}

Copyright NOTICE: This article is the original article of Bo Master, reprint annotated source

[Leetcode] [Java] Longest palindromic Substring