求大佬

#include<bits/stdc++.h>
using namespace std;
int bx,by,mx,my,x,y,d,d2;
int a[100][100];
int main(){
	cin>>bx>>by>>mx>>my;
	for(int i=0;i<=bx;i++)
	{
		a[i][0]=1;
		a[0][i]=1;
	}
	if(mx-2<0)d2=1;
	if(mx-1<0)d=1;
	a[mx][my]=-1;
	if(d2==0)a[mx-1][my-2]=-1;
	if(d2==0)a[mx-2][my-1]=-1;
	if(d2==0)a[mx-2][my+1]=-1;
	if(d==0)a[mx-1][my+2]=-1;
	a[mx+1][my+2]=-1;
	a[mx+2][my+1]=-1;
	if(d==0)a[mx+2][my-1]=-1;
	if(d2==0)a[mx+1][my-2]=-1;
	for(int i=1;i<=bx;i++)
	{
		for(int j=1;j<=by;j++)
		{
			if(a[i][j]==-1)continue;
			x=a[i][j-1];
			y=a[i-1][j];
			if(x==-1&&y==-1)a[i][j]=0;
			if(x==-1&&y!=-1)a[i][j]=y;
			if(x!=-1&&y==-1)a[i][j]=x;
			if(x!=-1&&y!=-1)a[i][j]=x+y;
			
		}
	}
	cout<<a[bx][by];
	return 0;
}

谢谢