C++ :

#include <cstdio>
#include <cstring>
#include <iostream>
using namespace std;
const int maxn = 110, dx[8] = {2,1,-1,-2,-2,-1,1,2}, dy[8] = {1,2,2,1,-1,-2,-2,-1};
int x, y, m, n;
long long a[maxn][maxn];
bool b[maxn][maxn];
int main()
{
	scanf("%d%d%d%d", &n, &m, &x, &y);	
	memset(b, true, sizeof(b));	
	a[0][0] = 1;		
	b[x][y] = false;		
	for (int i = 0; i != 8; ++i)	
    if (x+dx[i]>=0 && x+dx[i]<=m && y+dy[i]>=0 && y+dy[i]<=n) 
	b[x+dx[i]][y+dy[i]] = false;
	for (int i = 1; i <= n; ++i) 
	if (b[i][0]) a[i][0] = a[i-1][0];	
	for (int j = 1; j <= m; ++j) 
	if (b[0][j]) a[0][j] = a[0][j-1];	
	for (int i = 1; i <= n; ++i)					
	for (int j = 1; j <= m; ++j)
	if (b[i][j]) a[i][j] = a[i-1][j] + a[i][j-1];
	cout << a[n][m] << endl;	
	return 0;
}

Pascal :

const dx:array[1..8]of integer=(2,1,-1,-2,-2,-1,1,2);  //控制点相对马点的坐标位移
         dy:array[1..8]of integer=(1,2,2,1,-1,-2,-2,-1);
var    a:array[0..100,0..100]of int64;
         b:array[0..100,0..100]of boolean;
         x,y,i,j,m,n:integer;
Begin
   read(n,m,x,y);//读入B点坐标和马点坐标
   fillchar(a,sizeof(a),0); //A数组初值为0 
  fillchar(b,sizeof(b),true);//B数组初值为true 
  a[0,0]:=1; //起点路径初值为1
  b[x,y]:=false; //标识马点及其控制点 
  for i:=1 to 8 do  if (x+dx[i]>=0) and (x+dx[i]<=m) and (y+dy[i]>=0) and (y+dy[i]<=n) then        b[x+dx[i],y+dy[i]]:=false;
  for i:=1 to n do //求列坐标轴上的路径值
      if b[i,0] then a[i,0]:=a[i-1,0];
  for j:=1 to m do //求行坐标轴的路径值
      if b[0,j] then a[0,j]:=a[0,j-1];
   for i:=1 to n do //求各点的路径值
     for j:=1 to m do   
     if b[i,j] then a[i,j]:=a[i-1,j]+a[i,j-1];
   writeln(a[n,m]);//输出
end.