填数

program fillnum;
const
  maxn=1000;
var
  b:array[1..maxn]of boolean;
  s,n:integer;
  map:array[1..100,1..100]of integer;

procedure play(x,y:integer);
var
  i,j:integer;
begin
    //find one
    if x=n+1 then
        begin
          inc(s);
          for  i:=1 to n do
           begin
               for j:=1 to n do write(map[i,j]);
               writeln;
           end;
          writeln;
          exit;
        end;
       //huan hang
    if y=n+1 then play(x+1,1) else
     begin
          j:=0;
          //the min num
          if (y>1) then
            if map[x,y-1]>j then j:=map[x,y-1];
          if (x>1) then
            if map[x-1,y]>j then j:=map[x-1,y];
          //di gui kuang du    qi youxia fang neng zhan
          for i:=j+1 to n*n-(n-y+1)*(n-x+1)+1 do
           if b[i] then
            begin
                b[i]:=false;
                map[x,y]:=i;
                play(x,y+1);
                b[i]:=true;
            end;
     end;
end;

begin
      assign(input,'win.in');
      assign(output,'win.out');
      reset(input);
      rewrite(output);

      //initialization
      fillchar(b,sizeof(b),1);
      s:=0;
      readln(n);

      play(1,1);
      writeln(s);
      close(input);
      close(output);
end.

　　n2的棋盘，填1~n2个数，要求下比上大，左比右大。