#include "soccer.h"
#include<bits/stdc++.h>
using namespace std;
#define pb push_back
#define all(x) x.begin(),x.end()
#define vi vector<int>
#define pii pair<int,int>
#define ff first
#define ss second
#define ll long long int
#define cerr if(0) cerr
const int N = 2005, M = 3e5;
int arr[4][2] = {
{0, 1},
{0, -1},
{1, 0},
{-1, 0}
};
bitset<N> vis[N];
vector<pii> g[N][N];
int biggest_stadium(int n, std::vector<std::vector<int>> a)
{
int cnt = 0, px = 0, py = 0;
queue<pii> q;
bool any = false;
for(int i = 0; i < n; ++i){
for(int j = 0; j < n; ++j){
if(a[i][j] == 0){
if(!any){
any = true;
q.push({i, j});
vis[i][j] = 1;
}
for(int k = 0; k < 4; ++k){
int nx = i + arr[k][0];
int ny = j + arr[k][1];
if(nx >= 0 && ny < n && ny >= 0 && nx < n && a[nx][ny] == 0){
g[i][j].pb({nx, ny});
}
}
}else{
++cnt;
px = i, py = j;
}
}
}
if(cnt == 0){
return n * n;
}
if(cnt == 1){
return n*n - min({
(px + 1) * (py + 1),
(px + 1) * (n - py),
(n - px) * (n - py),
(n - px) * (py + 1),
});
}
int sz = 0;
while(!q.empty()){
int x = q.front().ff;
int y = q.front().ss;
q.pop();
++sz;
for(auto [ux, uy]: g[x][y]){
if(!vis[ux][uy]){
vis[ux][uy] = 1;
q.push({ux, uy});
}
}
}
for(int i = 0; i < n; ++i){
for(int j = 0; j < n; ++j){
if(!vis[i][j] && !a[i][j]){
return 0;
}
}
}
vector<pii> R;
for(int i = 0; i < n; ++i){
int l = n, r = -2;
for(int j = 0; j < n; ++j){
if(!a[i][j]) l = min(l, j);
if(!a[i][j]){
if(r != -2 && r < j - 1) return 0;
r = max(r, j);
}
}
if(l < n){
R.pb({l, r});
}
}
for(int i = 0; i < n; ++i){
int l = n, r = -2;
for(int j = 0; j < n; ++j){
if(!a[j][i]) l = min(l, j);
if(!a[j][i]){
if(r != -2 && r < j - 1) return 0;
r = max(r, j);
}
}
}
for(auto [lx, rx]: R){
for(auto [ly, ry]: R){
if(lx <= ly && ry <= rx) continue;
if(ly <= lx && rx <= ry) continue;
return 0;
}
}
return sz;
}
