This submission is migrated from previous version of oj.uz, which used different machine for grading. This submission may have different result if resubmitted.
#include "soccer.h"
#include <bits/stdc++.h>
    
using namespace std; 
 
 
typedef long long ll;
    
#define FOR(i,x,y) for(ll i=x; i<y; i++)
#define FORNEG(i,x,y) for(ll i=x; i>y; i--)
 
 
 
ll prefrow[2001][2001];
ll prefcol[2001][2001];
ll grid[2001][2001];
 
 
 
bool checkrow(ll a, ll b, ll row){
    if (a>b) swap(a,b);
 
    return (prefrow[row][b] - prefrow[row][a] + grid[row][a] == 0);
 
}
 
bool checkcol(ll a, ll b, ll col){
    if (a>b) swap(a,b);
 
    return (prefcol[b][col] - prefcol[a][col] + grid[a][col] == 0);
}
 
vector<array<ll,2>> possible;
 
ll ans = 0;
ll cnt =0 ;
 
 
void idkman(vector<array<ll,2>>& sus, ll n, ll point){
    if (sus.size()==n){
        ll temp = 0;
        for (auto&i : sus) temp += i[1] - i[0]+1;
        
        array<ll,2> firsts,lasts;
        bool flag = 0;
        for (auto&i : sus){
            for (auto&j : sus){
                if (i == array<ll,2>{0,-1} || j==array<ll,2>{0,-1}) continue;
                if (!((i[0] <= j[0] && j[1] <= i[1]) || (j[0]<=i[0]&&i[1]<=j[1]))){
                    flag = 1;
                }
            }
        }
        
        if (!flag) ans = max(ans, temp);
        return;
    }
 
    cnt++;
    for (auto&i : possible){
        if (i != array<ll,2>{0,-1} && prefrow[sus.size()][i[1]]-prefrow[sus.size()][i[0]]+grid[sus.size()][i[0]] != 0) continue;
        if (sus.size() && i != array<ll,2>{0,-1}){
            ll left = sus[sus.size()-1][0];
            ll right = sus[sus.size()-1][1];
            if (!(left==0 && right==-1) && !(left<=i[0] && i[1] <= right) && sus.size()>point){
                continue;
            }
            if (!(left==0 && right==-1) && !(i[0]<=left && right <= i[1]) && sus.size()<=point){
                continue;
            }
 
        }
        if (sus.size() && i == array<ll,2>{0,-1} && sus[sus.size()-1] != i){
            ll temp = 0;
            for (auto&i : sus) temp += i[1] - i[0]+1;
            
            array<ll,2> firsts,lasts;
            bool flag = 0;
            for (auto&i : sus){
                for (auto&j : sus){
                    if (i == array<ll,2>{0,-1} || j==array<ll,2>{0,-1}) continue;
                    if (!((i[0] <= j[0] && j[1] <= i[1]) || (j[0]<=i[0]&&i[1]<=j[1]))){
                        flag = 1;
                    }
                }
            }
            
            if (!flag) ans = max(ans, temp);
            continue;
        }
        sus.push_back(i);
        idkman(sus, n, point);
        sus.pop_back();
 
 
    }
 
 
}
 
 
int biggest_stadium(int N, std::vector<std::vector<int>> F)
{
    possible.clear();
    ans = 0;
 
    FOR(i,0,N){
        FOR(j,0,N){
            grid[i][j] = F[i][j];
        }
    }
    FOR(i,0,N){
        prefrow[i][0] = F[i][0];
        FOR(j,1,N){
            prefrow[i][j] = prefrow[i][j-1] + F[i][j];
        }
    }
 
    FOR(j,0,N){
        prefcol[0][j] = F[0][j];
        FOR(i,1,N){
            prefcol[i][j] = prefcol[i-1][j] + F[i][j];
        }
    }
 
    
 
    FOR(i,0,N){
        FOR(j,i,N){
            possible.push_back({i,j});
        }
    }
 
    possible.push_back({0,-1});
 
    vector<array<ll,2>> lmao;
    
    FOR(i,0,N){
        idkman(lmao, N, i);
        lmao.clear();
    }
    
 
 
 
                    // vector<vector<ll>> special;
 
                    // FOR(i,a,b){
                    //     FOR(j,c,d){
                    //         temp -= grid[i][j];
                    //         vector<vector<ll>> sus = {{i-1,j}, {i+1,j}, {i,j-1}, {i,j+1}};
                    //         if (grid[i][j] != 1){
                    //             bool flag = 0;
                    //             for (auto&k : sus){
                    //                 if (0<=k[0] && k[0]<N && 0<=k[1] && k[1]<N){
                    //                     if (grid[k[0]][k[1]]==1) flag = 1;
                    //                 }
                    //             }
                    //             if (flag==1 || i==0 || i==N-1 || j==0 || j==N-1) special.push_back({i,j});
                    //         }
                    //     }
                    // }
                    // bool flag = false;
                    // for (auto&X : special){
                    //     for (auto&Y : special){
 
                    //         ll i = X[0], j = X[1], k = Y[0], l= Y[1];
                    //          if (grid[i][j]==1 || grid[k][l] == 1) continue;
                    //         bool check1 = (checkrow(l, j, i) && checkcol(k, i, l));
                    //         bool check2 = (checkrow(l, j, k) && checkcol(k, i, j));
                    //         if (!check1 && !check2) flag = true;
                    //     }
                    // }
                    // if (!flag) ans = max(ans, temp);
 
                   
 
 
                    
 
    return ans;
 
 
}
Compilation message (stderr)
soccer.cpp: In function 'void idkman(std::vector<std::array<long long int, 2> >&, ll, ll)':
soccer.cpp:41:19: warning: comparison of integer expressions of different signedness: 'std::vector<std::array<long long int, 2> >::size_type' {aka 'long unsigned int'} and 'll' {aka 'long long int'} [-Wsign-compare]
   41 |     if (sus.size()==n){
      |         ~~~~~~~~~~^~~
soccer.cpp:47:21: warning: unused variable 'firsts' [-Wunused-variable]
   47 |         array<ll,2> firsts,lasts;
      |                     ^~~~~~
soccer.cpp:47:28: warning: unused variable 'lasts' [-Wunused-variable]
   47 |         array<ll,2> firsts,lasts;
      |                            ^~~~~
soccer.cpp:74:88: warning: comparison of integer expressions of different signedness: 'std::vector<std::array<long long int, 2> >::size_type' {aka 'long unsigned int'} and 'll' {aka 'long long int'} [-Wsign-compare]
   74 |             if (!(left==0 && right==-1) && !(left<=i[0] && i[1] <= right) && sus.size()>point){
      |                                                                              ~~~~~~~~~~^~~~~~
soccer.cpp:77:88: warning: comparison of integer expressions of different signedness: 'std::vector<std::array<long long int, 2> >::size_type' {aka 'long unsigned int'} and 'll' {aka 'long long int'} [-Wsign-compare]
   77 |             if (!(left==0 && right==-1) && !(i[0]<=left && right <= i[1]) && sus.size()<=point){
      |                                                                              ~~~~~~~~~~^~~~~~~
soccer.cpp:89:25: warning: unused variable 'firsts' [-Wunused-variable]
   89 |             array<ll,2> firsts,lasts;
      |                         ^~~~~~
soccer.cpp:89:32: warning: unused variable 'lasts' [-Wunused-variable]
   89 |             array<ll,2> firsts,lasts;
      |                                ^~~~~| # | Verdict | Execution time | Memory | Grader output | 
|---|
| Fetching results... | 
| # | Verdict | Execution time | Memory | Grader output | 
|---|
| Fetching results... | 
| # | Verdict | Execution time | Memory | Grader output | 
|---|
| Fetching results... | 
| # | Verdict | Execution time | Memory | Grader output | 
|---|
| Fetching results... | 
| # | Verdict | Execution time | Memory | Grader output | 
|---|
| Fetching results... | 
| # | Verdict | Execution time | Memory | Grader output | 
|---|
| Fetching results... | 
| # | Verdict | Execution time | Memory | Grader output | 
|---|
| Fetching results... |