#include "soccer.h"
#include <bits/stdc++.h>
using namespace std;
int dx[] = {1, -1, 0, 0};
int dy[] = {0, 0, 1, -1};
bool check(pair<int,int> u, pair<int,int> v, vector<vector<int>> &F) {
if (u.first == v.first) {
for (int i=min(u.second, v.second); i<=max(u.second, v.second); i++) {
if (F[u.first][i] == 1) return 0;
}
}
else if (u.second == v.second) {
for (int i=min(u.first, v.first); i<=max(u.first, v.first); i++) {
if (F[i][u.second] == 1) return 0;
}
}
else assert(0);
return 1;
}
int biggest_stadium(int N, vector<vector<int>> F) {
vector<vector<int>> vis(N, vector<int>(N, 0));
queue<pair<int,int>> q;
for (int i=0; i<N; i++) {
for (int j=0; j<N; j++) {
if (F[i][j] == 0) {
vis[i][j] = 1;
q.push({i, j});
break;
}
}
if (!q.empty()) break;
}
while (!q.empty()) {
int x = q.front().first;
int y = q.front().second;
q.pop();
for (int k=0; k<4; k++) {
int nx = x + dx[k];
int ny = y + dy[k];
if (nx < 0 || nx >= N || ny < 0 || ny >= N) continue;
if (vis[nx][ny]) continue;
vis[nx][ny] = 1;
q.push({nx, ny});
}
}
vector<pair<int,int>> blank;
for (int i=0; i<N; i++) {
for (int j=0; j<N; j++) {
if (F[i][j] == 0 && vis[i][j] == 0) {
return 0;
}
if (F[i][j] == 0) {
blank.push_back({i, j});
}
}
}
for (auto &u : blank) {
for (auto &v : blank) {
if (u == v) continue;
if (u.first == v.first || u.second == v.second) {
if (!check(u, v, F)) return 0;
}
else {
bool f1 = check(u, {u.first, v.second}, F) && check({u.first, v.second}, v, F);
bool f2 = check(u, {v.first, u.second}, F) && check({v.first, u.second}, v, F);
if (!f1 && !f2) return 0;
}
}
}
return blank.size();
/*int tot = 0;
bool flag = false;
int pl = -1, pr = -1;
vector<pair<int,int>> ran;
for (int i=0; i<N; i++) {
int l = -1, r = -1, cnt = 0;
for (int j=0; j<N; j++) {
if (F[i][j] == 0) {
if (l == -1) l = j;
r = j;
cnt ++;
}
}
if (cnt == 0) {
pl = -1; pr = -1;
continue;
}
ran.push_back({l, r});
if (r - l + 1 != cnt) {
return 0;
}
if (pl != -1) {
if (!flag) {
if (l <= pl && pr <= r) {}
else if (pl <= l && r <= pr) {
flag = true;
}
else return 0;
}
else {
if (pl <= l && r <= pr) {}
else return 0;
}
}
pl = l; pr = r;
tot += cnt;
}
sort(ran.begin(), ran.end(), [&](pair<int,int> &u, pair<int,int> &v) {
return u.second - u.first < v.second - v.first;
});
for (int i=0; i+1<ran.size(); i++) {
if (ran[i+1].first <= ran[i].first && ran[i].second <= ran[i+1].second) {}
else return 0;
}
return tot;*/
}
