27 lines
459 B
C++

#include <cstdio>
#include <cstring>
#include <iostream>
#include <cmath>
using namespace std;
int main()
{
int n,m,nn,mm,i,j;
long long f[100][100];
cin>>n>>m>>nn>>mm;
nn++; mm++; n++; m++;
memset(f,0,sizeof(f)); f[0][1]=1;
for (i=1;i<=n;i++)
for (j=1;j<=m;j++)
if ((abs(i-nn)+abs(j-mm)==3)&&(i!=nn)&&(j!=mm)||(i==nn&&j==mm));
else f[i][j]=f[i-1][j]+f[i][j-1];
cout<<f[n][m];
return 0;
}