WA60 3、4错 代码：

#include <iostream>
#include <cstdio>
#include <algorithm>
#include <vector>
#include <queue>
#include <stack>
#include <iomanip>
#include <cstring>
#include <string>
#include <cmath>
#include <map>
#include <cstdint>

using namespace std;

typedef unsigned Fxb;
typedef unsigned Sxb;

bool mp[25][25];
int ans[25];
Fxb n,mx;
Sxb m,my;
inline bool inmp(Fxb x,Sxb y)
{
    return x>=0&&x<=n&&y>=0&&y<=m; 
}
inline bool nma(Fxb x,Sxb y)
{
    return !mp[x][y];
}
inline bool isgoodft(Fxb x,Sxb y)
{
    return inmp(x,y)&&nma(x,y);
}
void initma()
{
    mp[mx][my]=1;
    int dx[8]={1,-1,1,-1,2,-2,2,-2};
    int dy[8]={2,-2,-2,2,1,-1,-1,1};
    for(int i=0;i<8;++i)
    {
        if(inmp(mx+dx[i],my+dy[i]))
        {
            mp[mx+dx[i]][my+dy[i]]=1;
        }
    }
}

int main()
{
    scanf("%d%d%d%d",&n,&m,&mx,&my);
    initma();
    for(Fxb i=0;i<=n;++i)
    {
        bool flag=0;
        for(Sxb j=0;j<=m;++j)
        {
            if((i==0||j==0)&&nma(i,j)&&flag==0)
            {
                ans[j]=1;
                continue;
            }
            if(nma(i,j))
            {
                ans[j]=ans[j]+ans[j-1];     
            }
            else
            {
                ans[j]=0;
                flag=1;
            }
        }
    }
    printf("%d\n",ans[m]);
    return 0;
}

感谢大佬