如题

#include<bits/stdc++.h>
using namespace std;
long long n , m;//n行m列 
long long x , y;
long long f[10005][10005];
long long a[10005][10005];
int main()
{
	cin >> n >> m >> x >> y;
	f[0][0] = 0;
	a[x][y] = -1;
	a[x - 1][y - 2] = a[x - 1][y + 2] = a[x - 2][y - 1] = a[x - 2][y + 1] = -1;
	a[x + 1][y - 2] = a[x + 1][y + 2] = a[x + 2][y - 1] = a[x + 2][y + 1] = -1;
	for(long long i = 0;i <= n;i++)
	{
		if(a[i][0] == -1)
		{
			break;
		}
		f[i][0] = 1;
	}
	for(long long i = 0;i <= m;i++)
	{
		if(a[0][1] == -1)
		{
			break;
		}
		f[0][i] = 1;
	}
	for(long long i = 1;i <= n;i++)
	{
		for(long long j = 1;j <= m;j++)
		{
			if(a[i][j] == -1)
			{
				f[i][j] = 0;
				continue;
			}
			else
			{
				f[i][j] = f[i - 1][j] + f[i][j - 1];
			}
		}
	}
	cout << f[n][m];
	return 0;
 }