题解

#include <stdio.h>

#define MAX_N 250

int main() {
    int N;
    char grid[MAX_N + 1][MAX_N + 1];
    int sum[MAX_N + 1][MAX_N + 1] = {0};
    int count[MAX_N + 1] = {0};
    scanf("%d", &N);
    for (int i = 1; i <= N; i++) {
        scanf("%s", grid[i] + 1);
        for (int j = 1; j <= N; j++) {
            sum[i][j] = sum[i - 1][j] + sum[i][j - 1] - sum[i - 1][j - 1] + (grid[i][j] == '1' ? 1 : 0);
        }
    }
    for (int k = N; k >= 2; k--) {
        for (int i = 1; i <= N - k + 1; i++) {
            for (int j = 1; j <= N - k + 1; j++) {
                int i2 = i + k - 1;
                int j2 = j + k - 1;
                int total = sum[i2][j2] - sum[i - 1][j2] - sum[i2][j - 1] + sum[i - 1][j - 1];
                if (total == k * k) {
                    count[k]++;
                }
            }
        }
    }
    for (int k = 2; k <= N; k++) {
        if (count[k] > 0) {
            printf("%d %d\n", k, count[k]);
        }
    }

    return 0;
}