[数据结构与算法]LeetCode-5.最长回文子串（动态规划）2021.7.21

题目链接 5.最长回文子串

题目描述：

解题思路:（来自力扣大神解析）

代码：

#include <iostream>
#include <cstdlib>
#include <algorithm>
#include <string>
using namespace std;

class Solution {
public:
    string longestPalindrome(string s) {
        int n = s.size();
        if (n < 2) {
            return s;
        }
        int maxLen = 1;
        int begin = 0;
        bool dp[n][n];
        for (int i = 0; i < n; i++) {
            dp[i][i] = true;
        }
        for (int L = 2; L <= n; L++) {
            for (int i = 0; i < n; i++) {
                int j = L + i - 1;
                if (j >= n) {
                    break;
                }
                if (s[i] != s[j]) {
                    dp[i][j] = false;
                } else {
                    if (j - i < 3) {
                        dp[i][j] = true;
                    } else {
                        dp[i][j] = dp[i + 1][j - 1];
                    }
                }
                if (dp[i][j] && j - i + 1 > maxLen) {
                    maxLen = j - i + 1;
                    begin = i;
                }
            }
        }
        return s.substr(begin, maxLen);
    }
};
int main()
{
    Solution s;
    string sc;
    cin >> sc;
    cout << s.longestPalindrome(sc); 
    return 0;
}