最长回文数的位数+C语言

以下是求解最长回文数位数的C语言代码：

#include <stdio.h>
#include <string.h>

#define MAXN 1010

char s[MAXN];
int dp[MAXN][MAXN];

int main() {
    fgets(s, MAXN, stdin);
    int len = strlen(s);
    if (s[len - 1] == '\n') s[--len] = '\0'; // 去掉fgets读入的换行符
    memset(dp, 0, sizeof(dp));
    for (int i = 0; i < len; i++) {
        dp[i][i] = 1;
        if (i < len - 1) {
            if (s[i] == s[i + 1]) dp[i][i + 1] = 1;
        }
    }
    for (int L = 3; L <= len; L++) {
        for (int i = 0; i + L - 1 < len; i++) {
            int j = i + L - 1;
            if (s[i] == s[j] && dp[i + 1][j - 1] == 1) dp[i][j] = 1;
        }
    }
    int ans = 0;
    for (int i = 0; i < len; i++) {
        for (int j = i; j < len; j++) {
            if (dp[i][j] == 1 && j - i + 1 > ans) ans = j - i + 1;
        }
    }
    printf("%d\n", ans);
    return 0;
}