Submission #1225312

#	Time	Username	Problem	Language	Result	Execution time	Memory
1225312		amine_aroua	Soccer Stadium (IOI23_soccer)	C++20	3.50 / 100	215 ms	48032 KiB

soccer

#include "soccer.h"
#include<bits/stdc++.h>
using namespace std;
int cnt = 0 , ret = 0;
int xx [] = {-1 , 1 , 0 , 0};
int yy[] = {0 , 0 , -1 , 1};
vector<vector<bool>> vis;
vector<vector<int>> grid;
int get_nest(pair<int ,int> a , pair<int ,int> b)
{
    if(a.first == b.first && a.second == b.second)
        return 2;
    if(a.first <= b.first && b.second <= a.second)
        return 0;
    swap(a , b);
    if(a.first <= b.first && b.second <= a.second)
        return 1;
    return -1;
}
void dfs(int x , int y)
{
    if(vis[x][y])
        return ;
    vis[x][y] = 1;
    cnt++;
    for(int k = 0 ; k < 4 ; k++)
    {
        int nx = x + xx[k] , ny = y + yy[k];
        if(grid[nx][ny] == 0)
            dfs(nx , ny);
    }
}

bool works(int h , int N  , vector<vector<int>> &F)
{
    cnt = 0;
    ret = 0;
    vis.assign(N + 2 ,vector<bool>(N + 2 , 1));
    grid.assign(N + 2 ,vector<int> (N + 2 , 1));
    for(int i= 1 ; i <= N ; i++)
    {
        for(int j = 1 ; j <= N ; j++)
        {
            if(h)
                grid[j][i] = F[i - 1][j - 1];
            else
            {
                grid[i][j] = F[i-1][j-1];
            }
            vis[i][j] = 0;
            ret+=(F[i - 1][j - 1]^1);
        }
    }
    vector<pair<int , int>> v(N + 1);
    for(int i = 1 ; i <= N ; i++)
    {
        int ans = 0;
        for(int j = 1 ;j <= N+  1 ; j++)
        {
            ans+=(grid[i][j] != grid[i][j - 1]);
        }
        if(ans != 2 && ans!= 0)
        {
            return 0;
        }
        int fr = -1;
        int lst = -1;
        for(int j = 1 ; j <= N ; j++)
        {
            if(grid[i][j] == 0)
            {
                if(fr== -1)
                    fr = j;
                lst = j;
            }
        }
        v[i] = {fr , lst};
    }
    for(int i = 1 ; i <= N ; i++)
    {
        for(int j = 1 ; j <= N ; j++)
        {
            if(grid[i][j] == 0)
            {
                dfs(i , j);
                i = N + 1;
                break;   
            }
        }
    }
    
    if(cnt != ret)
        return 0;
    int lst0 = 0;
    vector<int> type(N + 1);
    for(int i = 2 ; i <= N ; i++)
    {
        if(v[i].first == -1 || v[i - 1].first == -1)
        {
            type[i] = 2;
            continue;
        }
        if(v[i].first == v[i - 1].first && v[i].second == v[i - 1].second)
        {
            type[i] = 2;
            continue;
        }
        type[i] = get_nest(v[i] , v[i - 1]);
        if(type[i] == -1)
        {
            return 0;
        }
        if(type[i] == 0)
            lst0 = i;
    }
    if(lst0 == 0)
    {
        return 1;
    }
    int nb1 = count(type.begin() + 2 , type.begin() + lst0+1 , 1);
    if(nb1)
        return 0;
    for(int i = lst0 ; i <= N ; i++)
    {
        if(v[i].first == -1)
            continue;
        if(get_nest(v[i] , v[lst0 - 1]) == -1)
        return 0;
    }
    return 1;
}

int biggest_stadium(int N, std::vector<std::vector<int>> F)
{
    bool check = (works(0 , N , F));
    // cout<<check<<'\n';
    if(check)
    {
        assert(ret != 0);
        return ret;
    }
    return 0;
}

/*
  --
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------
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*/

• Subtask 0: 0 / 0
• Subtask 1: 1.5 / 6
• Subtask 2: 2 / 8
• Subtask 3: 0 / 22
• Subtask 4: 0 / 18
• Subtask 5: 0 / 16
• Subtask 6: 0 / 30