HDU 4618

#include <cstring>#include <cstdio>#include <algorithm>#include <iostream>using namespace std;const int maxn = 311;#define lson l,m,rt<<1#define rson m+1,r,rt<<1|1int a[maxn][maxn];int n, m;bool ok(int i, int j, int k) {    int h, l;    for (h = 0; h < k; ++h) {        for (l = 0; l <= k - l; ++l) {            if (a[i + h][j + l] != a[i + h][j + k - l - 1])                return false;            if (a[i + l][j + h] != a[i + k - l - 1][j + h])                return false;        }    }    return true;}bool go(int n, int m, int k) {    int i, j;    for (i = 0; i + k <= n; ++i)        for (j = 0; j + k <= m; ++j) {            if (ok(i, j, k))                return true;        }    return false;}int main() {    int i, j, k;    int T;    scanf("%d", &T);    while (T--) {        scanf("%d%d", &n, &m);        for (i = 0; i < n; ++i)            for (j = 0; j < m; ++j)                scanf("%d", a[i] + j);        int ans = 0;        for (k = min(n, m); k >= 1; --k) {            if (go(n, m, k)) {                ans = k;                break;            }        }        printf("%d\n", ans);    }    return 0;}