深度优先搜索

自己手敲的深搜代码 可能有点杂乱 but it has ACed.

#include<bits/stdc++.h>
using namespace std;
int n,m;
char a[105][105];
bool vis[105][105];
int dx[4]={0,0,-1,1},dy[4]={1,-1,0,0};
bool f;
void dfs(int x,int y){
	vis[x][y]=1;
	if(x==n and y==m){
		cout<<"YES";
		f=1;
		return;
	}
	for(int i=0;i<4;i++){
		int nx=x+dx[i],ny=y+dy[i];
		if(a[nx][ny]=='0' and vis[nx][ny]==0 and nx>=1 and nx<=n and ny>=1 and ny<=m){
			dfs(nx,ny);
		}
	}
}
int main(){
	cin>>n>>m;
	for(int i=1;i<=n;i++){
		for(int j=1;j<=m;j++){
			cin>>a[i][j];
		}
	}
	dfs(1,1);
	if(f==0){
		cout<<"NO";
	}
	return 0;
}