#include "soccer.h"
#include <bits/stdc++.h>
using namespace std;
using ll = long long;
const int N = 2020;
int n;
int f[N][N], qs[N][N];
int l[N], r[N];
// check if all empty cell are regular stadium
bool all_can() {
for (int i = 1;i <= n;i++) {
for (int j = 1;j <= n + 1;j++) {
if (f[i][j - 1] != f[i][j]) {
if (!l[i]) l[i] = j;
else if (!r[i]) r[i] = j - 1;
else return 0;
}
}
}
for (int j = 1;j <= n;j++) {
int cnt = 0;
for (int i = 1;i <= n;i++) {
cnt += f[i - 1][j] != f[i][j];
}
if (cnt > 2) return 0;
}
for (int i = 1;i <= n;i++) {
if (l[i] == 0) continue;
for (int j = 1;j <= n;j++) {
if (l[j] == 0) continue;
bool ch = (l[i] <= l[j] && r[j] <= r[i]) || (l[j] <= l[i] && r[i] <= r[j]);
if (!ch) return 0;
}
}
return 1;
}
int mx;
int l1[505][505], r1[505][505];
int L1[505], R1[505];
int dp[505][505], L[505][505], R[505][505];
int inter(int l1, int r1, int l2, int r2) {
if (l1 > l2) {
swap(l1, l2);
swap(r1, r2);
}
// l1 <= l2
if (r2 <= r1) return r2 - l2 + 1;
if (r1 < l2) return 0;
return r1 - l2 + 1;
}
int biggest_stadium(int NN, vector<vector<int>> F) {
n = NN;
int empty_cell = 0;
for (int i = 1;i <= n;i++) {
f[0][i] = f[n + 1][i] = f[i][0] = f[i][n + 1] = 1;
for (int j = 1;j <= n;j++) {
f[i][j] = F[i - 1][j - 1];
qs[i][j] = qs[i][j - 1] + f[i][j];
empty_cell += f[i][j] == 0;
}
}
if (all_can()) return empty_cell;
if (empty_cell == n * n - 1) {
int mx = 0;
for (int i = 1;i <= n && !mx;i++) {
for (int j = 1;j <= n && !mx;j++) {
if (f[i][j]) {
mx = max(mx, (i - 1) * n + (j - 1) * n - (i - 1) * (j - 1));
mx = max(mx, (n - i) * n + (j - 1) * n - (n - i) * (j - 1));
mx = max(mx, (i - 1) * n + (n - j) * n - (i - 1) * (n - j));
mx = max(mx, (n - i) * n + (n - j) * n - (n - i) * (n - j));
}
}
}
return mx;
}
if (n > 500) return 0;
for (int i = 1;i <= n;i++) {
for (int j = 0;j <= n;j++) {
if (f[i][j] == 1) l1[i][j] = j + 1;
else l1[i][j] = l1[i][j - 1];
}
for (int j = n + 1;j >= 1;j--) {
if (f[i][j] == 1) r1[i][j] = j - 1;
else r1[i][j] = r1[i][j + 1];
}
}
mx = 0;
for (int c = 1;c <= n;c++) {
for (int i = 1;i <= n;i++) {
if (f[i][c]) dp[i][i] = -1e9, L[i][i] = L1[i] = -1, R[i][i] = R1[i] = -2;
else {
L1[i] = l1[i][c], R1[i] = r1[i][c];
dp[i][i] = R1[i] - L1[i] + 1, L[i][i] = L1[i], R[i][i] = R1[i];
mx = max(mx, dp[i][i]);
}
}
for (int k = 1;k < n;k++) {
for (int i = 1;i <= n - k;i++) {
int j = i + k;
L[i][j] = max(L[i + 1][j], L1[i]), R[i][j] = min(R[i + 1][j], R1[i]);
dp[i][j] = -1e9;
if (inter(L[i + 1][j], R[i + 1][j], L1[i], R1[i]) != 0) {
dp[i][j] = max(dp[i][j], dp[i + 1][j] + inter(L[i + 1][j], R[i + 1][j], L1[i], R1[i]));
}
if (inter(L[i][j - 1], R[i][j - 1], L1[j], R1[j]) != 0) {
dp[i][j] = max(dp[i][j], dp[i][j - 1] + inter(L[i][j - 1], R[i][j - 1], L1[j], R1[j]));
}
mx = max(mx, dp[i][j]);
}
}
}
return mx;
}
