(动态规划)最长回文子串

版权声明：本文为博主原创文章，未经博主允许不得转载。 https://blog.csdn.net/weifuliu/article/details/83152250

代码

#include <stdio.h>
#include <string.h>
#include <math.h>
#include <stdlib.h>
#include <time.h>
#include <stdbool.h>
#include <string>
#include <iostream>
using namespace std;
#define maxn 1010
int dp[maxn][maxn];

int main() {
	ios::sync_with_stdio(false);
	string S;
	int t = 1;
	while (cin >> S&&S!="END") {
		for (int i = 0; i < maxn; i++) {
			for (int j = 0; j < maxn; j++) {
				dp[i][j] = 0;
			}
		}
		
		int len = S.length(), ans = 1;
		int i = 0, j = 0, L = 0;
		for (i = 0; i<len; ++i) {
			dp[i][i] = 1;
			if (i < len - 1) {
				if (S[i] == S[i + 1]) {
					dp[i][i + 1] = 1;
					ans = 2;
				}
			}
		}
		for (L = 3; L <= len; ++L) {
			for (i = 0; i + L - 1 < len; ++i) {
				j = i + L - 1;
				if (S[i] == S[j] && dp[i + 1][j - 1] == 1) {
					dp[i][j] = 1;
					ans = L;
				}
			}
		}
		printf("Case #%d: %d\n",t++, ans);
		S.erase(0, len);
	}    
	system("pause");
	return 0;
}