@[quruijie5418814524](/user/679600)
每个方格最多经过一次
需要一个VIS数组判断是否走过
by Zelensky @ 2022-10-12 19:30:01
```
#include<bits/stdc++.h>
using namespace std;
int f[4][2]={{1,0},{-1,0},{0,1},{0,-1}};
int ans=0;
int n,m,tt=0,t,hh=1,sx,sy,fx,fy,a,b;
int vis[10000][10000];
bool judge(int x,int y){
return vis[x][y]==0&&x<=n&&y<=m&&x>=1&&y>=1;
}
void dfs(int x,int y)
{
// cout<<x<<" "<<y<<endl;
if(x==fx&&y==fy){
ans++;
return;
}
else{
for(int i=0;i<4;i++){
if(judge(x+f[i][0],y+f[i][1])){
vis[x+f[i][0]][y+f[i][1]]=1;
dfs(x+f[i][0],y+f[i][1]);
if(vis[x+f[i][0]][y+f[i][1]]==1)
vis[x+f[i][0]][y+f[i][1]]=0;
}
}
}
}
int main()
{
cin>>n>>m>>t;
cin>>sx>>sy>>fx>>fy;
for(int i=1;i<=t;i++){
cin>>a>>b;
vis[a][b]=114514;
}
vis[sx][sy]=1;
dfs(sx,sy);
cout<<ans;
return 0;
}
```
像这样
by Zelensky @ 2022-10-12 19:31:11
@[quruijie5418814524](/user/679600)
回溯时还要清除标记
by Zelensky @ 2022-10-12 19:40:21
谢谢
by quruijie5418814524 @ 2022-10-12 19:40:26