@[坏掉了](/space/show?uid=100592) 代码
by Meatherm @ 2019-02-03 21:43:23
```cpp
#include <cstdio>
#include <iostream>
#include <cstring>
#include <queue>
#include <algorithm>
using namespace std;
bool a[10005][10005];
int n,t;
int ix[10005],iy[10005];
int dx[4] = {0,1,0,-1};
int dy[4] = {1,0,-1,0};
struct Pos{
int x, y;
};
queue<Pos> bq;
int main(){
cin>>t;
while(t--){
while(!bq.empty()){
bq.pop();
}
memset(ix,0,sizeof(ix));
memset(iy,0,sizeof(iy));
cin >>n;
for(int j = 1; j <= 2*n-2; j++)
cin >> ix[j]>>iy[j];
for(int i = 0; i <= n+1; i++)
for(int j = 0; j <= n+1; j++)
if(i == 0 || j == 0 || i == n+1 || j == n+1)
a[i][j] = 1;
else a[i][j] = 0;
bq.push({1,1});
a[1][1] = 1;
int tag=0;
int p=0;
while( !bq.empty() ){
Pos head = bq.front();
a[ix[p]][iy[p]]=1;
p++;
if(head.x == n && head.y == n){
cout<<"Yes"<<endl;
tag = 1;
break;
}
for(int i = 0; i < 4; i++){
int tx = head.x+dx[i], ty = head.y+dy[i];
if(a[tx][ty] != 1){
a[tx][ty] = 1;
/*for(int i = 1; i <= n; i++){
for(int j = 1; j <= n; j++)
cout<<a[i][j];
cout<<endl;
}
cout<<endl;*/
bq.push({tx, ty});
}
}
bq.pop();
}
if(tag == 0) cout << "No"<<endl;
}
return 0;
}
```
四个REqwq
by Tsumi @ 2019-02-03 21:46:15
@[兹磁洛谷](/space/show?uid=108949)
by Tsumi @ 2019-02-03 21:49:44
@[坏掉了](/space/show?uid=100592) 我有空给你看下，现在在老家qaq
by Meatherm @ 2019-02-04 08:37:18
@[兹磁洛谷](/space/show?uid=108949) 吼，我自己也调一调
by Tsumi @ 2019-02-04 08:38:13