囧--马拦过河卒--囧怎么做

囧--马拦过河卒--囧怎么做

const
dx:array[1..8] of Shortint=(-2,-1,1,2,2,1,-1,-2);
dy:array[1..8] of Shortint=(1,2,2,1,-1,-2,-2,-1);
var
n,m,x,y,i,j:word;
g:array[-2..20,-2..20] of real;
f:array[-2..20,-2..20] of real;
begin
Readln(n,m,x,y);
Fillchar(g,Sizeof(g),0);
g[x,y]:=1;
for i:=1 to 8 do
if (x+dx[i]>=0) and (x+dx[i]<=n) and
(y+dy[i]>=0) and (y+dy[i]<=m) then
g[x+dx[i],y+dy[i]]:=1;
f[0,0]:=1;
for i:=1 to n do
if g[i,0]=0 then f[i,0]:= f[i-1, 0];
for i:= 1 to m do
if g[0,i]=0 then f[0,i]:=f[0,i-1];
for i:=1 to n do
for j:=1 to m do
if g[i,j]=0 then f[i,j]:=f[i-1,j] + f[i,j-1];
Writeln(f[n,m]:0:0);
end.