[bfs] 라비다 1052 maze problem

https://judge.lavida.us/problem.php?id=1052

아주대 A.N.S.I에서 쓰는 저지 사이트입니다. 

#include <iostream>
#include <queue>
using namespace std;
 
 
int main(){
    ios_base::sync_with_stdio(false);
    int t;
    int dx[4] = {0,0,1,-1};
    int dy[4] = {1,-1,0,0};
    
    cin >> t;
    
    while(t--){
        char map[100][100];
        int n,m;
        pair<int,int> start;
        cin >> n >> m;
        
        for(int i = 0; i < n; i++){
            for(int j = 0; j < m; j++){
                cin >> map[i][j];
                if(map[i][j] == 'S')  start = {i,j};
            }
        }
        
        queue<pair<int,int> > q;
        bool visited[100][100] = {0};
        bool check_goal = 0;
        int count = 0;
        q.push(start);
        
        while(!q.empty() && !check_goal){
            int size = q.size();
            count++;
            
            for(int i = 0; i < size; i++){
                int x = q.front().second, y = q.front().first;
                q.pop();
                
                for(int i= 0; i  < 4; i++){
                    int xx = x  + dx[i], yy = y+dy[i];
                    
                    if(xx < 0 || yy < 0 || xx >= m || yy >= n) continue;
                    if(visited[yy][xx] || map[yy][xx] == '#') continue;
                    if(map[yy][xx] == 'E'){
                        check_goal = true;
                        break;
                    }
                    q.push({yy,xx});
                    visited[yy][xx] = true;
                }
            }
        }
        if(check_goal) cout << count << endl;
        else          cout << -1 << endl;
    }    
}

간단히 bfs를 이용해 최단경로 찾는 문제입니다.