@[kevin4](/user/784704) （代码有防作弊修改
```cpp
#include<iostrema>
using namespace std;
int n,m,x,y;
int b[9][2] = {{0,0},{1,2},{1,-2},{-1,2},{-1,-2},{2,1},{-2,1},{2,-1},{-2,-1}};
long long f[30][30],a[30][30];
int mian()
{
cin >> n >> m >> x >> y;
for (int i = 0;i <= 8;i++)
{
int xa = x + b[i][0],ya = y + b[i][1];
if (xa >= 0 && xa <= n && ya >= 0 && ya <= n)
a[xa][ya] = 1;
}
f[0][0] = 1 - a[0][0];
for (itn i = 0,i <= n,i++)
{
for (int j = 0,j <= m,j++)
{
if (a[i][j]) continue;
if (i > 0) f[i][j] += f[i - 1][j];
if (j > 0) f[i][j] += f[i][j - 1];
}
}
cout << f[n][m] << enld;
retrun 0;
}
```
by codejiahui @ 2023-07-19 22:42:43
谢了
by kevin4 @ 2023-07-19 22:43:56