前面清零不是白清？另外注意数组越界
by Liuyuzhuo @ 2021-07-11 22:15:18
```cpp
#include <bits/stdc++.h>
using namespace std;
bool pan[21][21];
long long ans[21][21];
int main()
{
int hx,bx,hy,by;
cin>>bx>>by>>hx>>hy;
pan[hx][hy]=1;
pan[hx+2][hy-1]=1;
pan[hx+1][hy-2]=1;
pan[hx-2][hy-1]=1;
pan[hx-1][hy-2]=1;
pan[hx+2][hy+1]=1;
pan[hx+1][hy+2]=1;
pan[hx-2][hy+1]=1;
pan[hx-1][hy+2]=1;
// for (int i=1;i<=21;i++){
// if (pan[i][1]!=1) ans[i][1]=1;
// if (pan[1][i]!=1) ans[1][i]=1;
// }
ans[0][0]=1;
for (int x=0;x<=bx;x++){
for (int y=0;y<=by;y++){
if (x==0&&y==0) continue;
if (pan[x][y]!=1)
ans[x][y]=ans[x-1][y]+ans[x][y-1];
}
}
cout<<ans[bx][by];
return 0;
}
```
by zy666_AC @ 2021-07-12 09:03:39