题目

#include<cstdio>
#include<cstring>
#include<iostream>
#define en '\n'
#define m(a,b) memset(a,b,sizeof a)
using namespace std;
const int N=100+5;
int nex[4][2]={1,0,-1,0,0,-1,0,1};
char ma[N][N];
int sx,sy,ex,ey,n;
int isok(int x,int y){
return x>=1&&x<=n&&y>=1&&y<=n&&ma[x][y]!='#';
}
int dfs(int x,int y)
{
if(x==ex&&y==ey) return 1;
ma[x][y]='#';
for(int k=0;k<=3;++k)
{
int nx=x+nex[k][0],ny=y+nex[k][1];
if(!isok(nx,ny)) continue;
if(dfs(nx,ny)) return 1;
}
return 0;
}
int main()
{
int T;scanf("%d",&T);
while(T--)
{
scanf("%d",&n);
for(int i=1;i<=n;++i) scanf("%s",ma[i]+1);
scanf("%d%d%d%d",&sx,&sy,&ex,&ey),++sx,++sy,++ex,++ey;
puts(ma[sx][sy]!='#'&&ma[ex][ey]!='#'&&dfs(sx,sy)==1?"YES":"NO");
}
}
#include<cstdio>
#include<cstring>
#include<iostream>
#define en '\n'
#define m(a,b) memset(a,b,sizeof a)
using namespace std;
const int N=100+5;
int nex[4][2]={1,0,-1,0,0,-1,0,1};
char ma[N][N];
int sx,sy,ex,ey,n;
int isok(int x,int y){
return x>=1&&x<=n&&y>=1&&y<=n&&ma[x][y]!='#';
}
int flag;
void dfs(int x,int y)
{
if(flag) return;
if(x==ex&&y==ey) {flag=1;return;}
ma[x][y]='#';
for(int k=0;k<=3;++k)
{
int nx=x+nex[k][0],ny=y+nex[k][1];
if(!isok(nx,ny)) continue;
dfs(nx,ny);
}
return;
}
int main()
{
int T;scanf("%d",&T);
while(T--)
{
flag=0;
scanf("%d",&n);
for(int i=1;i<=n;++i) scanf("%s",ma[i]+1);
scanf("%d%d%d%d",&sx,&sy,&ex,&ey),++sx,++sy,++ex,++ey;
if(ma[sx][sy]=='#'||ma[ex][ey]=='#') puts("NO");
else
{
dfs(sx,sy);
puts(flag?"YES":"NO");
}
}
}
#include<cstdio>
#include<cstring>
#include<queue>
#include<iostream>
#define en '\n'
#define m(a,b) memset(a,b,sizeof a)
using namespace std;
const int N=100+5;
int nex[4][2]={1,0,-1,0,0,-1,0,1};
char ma[N][N];
struct node{int x,y;};
queue<node>q;
int sx,sy,ex,ey,n;
int isok(int x,int y){
return x>=1&&x<=n&&y>=1&&y<=n&&ma[x][y]!='#';
}
int bfs()
{
while(!q.empty()) q.pop();
ma[sx][sy]='#',q.push((node){sx,sy});
while(!q.empty())
{
node cur=q.front();q.pop();
int x=cur.x,y=cur.y,nx,ny;
if(x==ex&&y==ey) return 1;
for(int k=0;k<=3;++k)
{
nx=x+nex[k][0],ny=y+nex[k][1];
if(isok(nx,ny))
{
ma[nx][ny]='#';
q.push((node){nx,ny});
}
}
}
return -1;
}
int main()
{
int T;scanf("%d",&T);
while(T--)
{
scanf("%d",&n);
for(int i=1;i<=n;++i) scanf("%s",ma[i]+1);
scanf("%d%d%d%d",&sx,&sy,&ex,&ey),++sx,++sy,++ex,++ey;
puts(ma[sx][sy]!='#'&&ma[ex][ey]!='#'&&bfs()!=-1?"YES":"NO");
}
}