[C++] BOJ 2178 - 미로 탐색

#include <iostream>
#include <algorithm>
#include <queue>
#define MAX 100
using namespace std;

int dy[] = {1,-1,0,0};
int dx[] = {0,0,1,-1};
int map[MAX][MAX];
int visited[MAX][MAX];
int n,m;
queue<pair<int, int> > q;

bool isInside(int y, int x) {
	return (y >= 0 && x >= 0 && y < n && x < m);
}

int bfs(int startY, int startX) {
	int nowY = startY;
	int nowX = startX;
	
	q.push({nowY, nowX});
	visited[nowY][nowX] = 1;
	
	while(!q.empty()) {
		nowY = q.front().first;
		nowX = q.front().second;
		q.pop();
		
		if(!isInside(nowY,nowX)) continue;
		
		for(int i=0;i<4;i++) {
			int nextY = nowY + dy[i];
			int nextX = nowX + dx[i];
			
			if(isInside(nextY,nextX) && !visited[nextY][nextX] && map[nextY][nextX]) {
				visited[nextY][nextX] = visited[nowY][nowX] + 1;
				q.push({nextY, nextX});
			}
		}
	}
	
	return visited[n-1][m-1];
}

int main() {
	scanf("%d %d",&n,&m);
	
	for(int i=0;i<n;i++)
		for(int j=0;j<m;j++) 
			scanf("%1d",&map[i][j]);
	
	printf("%d",bfs(0,0));
}

BFS를 이용한 풀이입니다.