www.vijos.cn上一些习题的参考源码

				program p1121;
				type
				    ORD=record
				        x,y:integer;
				        end;
				var
				    s,e,ma:ORD;
				    p:integer;
				
				function move(s:ORD; op:integer):ORD;
				begin
				    case op of
				    1:begin inc(s.x); end;
				    2:begin inc(s.y); end;
				    end;
				    exit(s);
				end;
				
				procedure search(s:ORD);
				var
				    op:integer;
				    t:ORD;
				begin
				    if s=e then begin
				        inc(p);
				        exit;
				    end;
				    for op:=1 to 2 do begin
				        t:=move(s,op);
				        if ((t.x in [1..e.x]) and (t.y in [1..e.y])) then
				            search(t);
				    end;
				end;
				
				
				begin
				    readln(e.x,e.y,ma.x,ma.y);
				    s.x:=0; s.y:=0;
				    p:=0;
				    search(s);
				    writeln(p);
				end.