题解

#include<iostream>
using namespace std;
char a[20][20];
int n,m,sx,sy,fx,fy,dx[4]={0,1,0,-1},dy[4]={1,0,-1,0};
bool p[20][20],flag;
void f(int x,int y){
    if(x==fx&&y==fy){
        flag=1;
        return;
    }
    for(int i=0;i<4;i++){
        int nx=x+dx[i],ny=y+dy[i];
        if(nx>=1&&nx<=n&&ny>=1&&ny<=m&&p[nx][ny]==0&&a[nx][ny]!=0){
            p[nx][ny]=1;
            f(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];
            if(a[i][j]=='X'){
                a[i][j]=0;
            }else if(a[i][j]=='S'){
                sx=i;
                sy=j;
            }else if(a[i][j]=='T'){
                fx=i;
                fy=j;
            }
        }
    }
    p[sx][sy]=1;
    f(sx,sy);
    if(flag==0){
        cout<<"NO";
    }else{
        cout<<"YES";
    }
	return 0;
}