Leetcode5 Longest palindromic Substring

The longest palindrome substring of a string. Palindrome Sub-string is divided into two kinds, one is ABA type, one is ABBA type, so both cases are considered. With a loop, each character in the string is judged as the center, and the oldest string after each loop is recorded. Time Complexity of O (n*n)

A program was previously written to run, but ran out of time in Leetcode. The following is the modification of other people's program, very concise.

Leetcode5 Longest palindromic Substring