DFS 深度优先搜索题解

#include<bits/stdc++.h>
using namespace std;
int n,m,mp[45][45],dx[4]={0,1,0,-1},dy[4]={1,0,-1,0};
bool v[45][45],f=0;
void dfs(int x,int y){
    if(x==n&&y==m){
        f=1;
        return;
    }
    if(f)return;
    for(int i=0;i<4;i++){
        int nx=dx[i]+x,ny=dy[i]+y;
        if(nx>n||nx<1||ny>m||ny<1||mp[nx][ny]==1||v[nx][ny])continue;
        v[nx][ny]=1;
        dfs(nx,ny);
        v[nx][ny]=0;
    }
}
int main(){
    cin>>n>>m;
    for(int i=1;i<=n;i++){
        for(int j=1;j<=m;j++){
            cin>>mp[i][j];
        }
    }
    dfs(1,1);
    if(f)cout<<"YES";
    else cout<<"NO";
    return 0;
}