[Uncompleted]
http://codevs.cn/problem/1010/
#include <stdio.h>
#include<string.h>
#define x 0
#define y 1
int map[20][20];
void Print(int h[][2])
{
int i;
for(i=0;i<9;i++)
{
printf("%d %d
",h[i][x],h[i][y]);
}
}
int main()
{
int bn,bm;
int h[2];
memset(map,0,20*20);
scanf("%d%d",&bn,&bm);
scanf("%d%d",&h[x],&h[y]);
map[h[x]][h[y]]=-1;
map[h[x]+2][h[y]+1]=-1;
map[h[x]+2][h[y]-1]=-1;
map[h[x]+1][h[y]-2]=-1;
map[h[x]-1][h[y]-2]=-1;
map[h[x]-2][h[y]-1]=-1;
map[h[x]-2][h[y]+1]=-1;
map[h[x]-1][h[y]+2]=-1;
map[h[x]+1][h[y]+2]=-1;
int i,j;
map[0][0]=1;
for(i=0;i<=bn;i++)
{
for(j=0;j<=bm;j++)
{
if(map[i][j]==-1)continue;
if(j>0&&map[i][j-1]!=-1)map[i][j]+=map[i][j-1];
if(i>0&&map[i-1][j]!=-1)map[i][j]+=map[i-1][j];
}
}
int ans=map[bn][bm];
printf("%d
",ans);
return 0;
}