[bfs] 백준 7569 토마토

https://www.acmicpc.net/problem/7569

처음에 토마토가 들어가 있는 좌표를 queue에 push합니다.

그리고 queue에 있는 것을 하나 씩 꺼내서 bfs합니다.

#include <iostream>
#include <queue>
using namespace std;
 
int map[100][100][100];
int h,n,m;
 
bool chk(){
    for(int i = 0; i < h; i++){
        for(int j = 0; j < n; j++){
            for(int k = 0; k < m; k++){
                if(map[i][j][k] == 0) return true;
            }
        }
    }
    return false;
}
 
int main(){
    ios_base::sync_with_stdio(false);
    
    bool visited[100][100][100] = {0};
    int dz[6] = {1,-1,0,0,0,0};
    int dy[6] = {0,0,1,-1,0,0};
    int dx[6] = {0,0,0,0,1,-1};
    queue<pair<int,pair<int,int> > > q;
    int day = -1;
    
    cin >> m >> n >> h;
    
    for(int i = 0; i < h; i++){
        for(int j = 0; j < n; j++){
            for(int k = 0; k < m; k++){
                cin >> map[i][j][k];
                if(map[i][j][k] == 1){
                    q.push({i,{j,k}});
                    visited[i][j][k] = true;
                }
            }
        }
    }
    
    if(!chk()){
        cout << 0;
        return 0;
    }
    
    while(!q.empty()){
        int size = q.size();
        day+=1;
        
        for(int i = 0; i < size; i++){
            int x = q.front().second.second, y = q.front().second.first, z = q.front().first;
            q.pop();
            for(int j = 0; j < 6; j++){
                int xx = x + dx[j], yy = y + dy[j], zz = z + dz[j];
                if(xx >= m || yy >= n || zz >= h || xx < 0 || yy < 0 || zz < 0) continue;
                if(visited[zz][yy][xx] || map[zz][yy][xx] == -1) continue;
                visited[zz][yy][xx] = true;
                map[zz][yy][xx] = 1;
                q.push({zz,{yy,xx}});
            }
        }
        
    }
    
    if(chk())    cout << -1;
    else cout << day;
    
}