baekjun 2178. 미로탐색

 bfs에서 순서 알고 싶을때는 현재값 = 이전값 + 1

#include<bits/stdc++.h>
#define MAX 0x12345678
using namespace std;
int matrix[101][101];
int visitedList[101][101];
int tbrl[4][2] = {{0, 1}, {1, 0}, {-1, 0}, {0, -1}};
int N,M;
int result = MAX;
 
bool isInMatrix(int y, int x){
    return (y <= N) && (y >0) && (x <= M) && (y >0);
}
 
void bfs(){
    queue<pair<int, int> > que;
    que.push(pair<int, int>(1, 1));
    visitedList[1][1] = 1;
    while(!que.empty()){
        pair<int, int> tmp = que.front();
        int y = tmp.first;
        int x = tmp.second;
        que.pop();
        for(int i = 0 ; i < 4; i++){
            int yi = y + tbrl[i][0];
            int xi = x + tbrl[i][1];
            if(isInMatrix(yi, xi) && !visitedList[yi][xi] && matrix[yi][xi]){
                que.push(pair<int, int>(yi, xi));
                visitedList[yi][xi] = visitedList[y][x] + 1;
            }
        }
    }
    cout << visitedList[N][M] << endl;
}
 
int main(){
    cin >> N >> M;
    memset(visitedList, 0, sizeof(visitedList));
    for(int i=1; i <= N; i++){
        string tmp;
        cin >> tmp;
        for(int j=1; j<=M; j++){
            if(tmp[j - 1] == '1')
                matrix[i][j]=1;
            else
                matrix[i][j]=0;
        }
    }
    bfs();
    return 0;
}