stack.pas

PASCAL光盘资料PASCAL光盘资料PASCAL光盘资料

program E2_14;{stack_count}
var c:array[1..10000] of longint;
    n,i,j,k,ys,len:longint;
begin
 assign(input,'stack.in');
 assign(output,'stack.out');
 reset(input);
 readln(n);
 close(input);
 fillchar(c,sizeof(c),0);
 c[1]:=1;len:=1;
 for i:=2*n downto n+2 do
  begin
    for j:=1 to len do c[j]:=c[j]*i;
    for j:=1 to len+4 do
      begin
       c[j+1]:=c[j+1]+c[j] div 10;
       c[j]:=c[j] mod 10;
      end;
   len:=len+5;
   while c[len]=0 do dec(len);
  end;
 for i:=n downto 2 do
  begin
   ys:=0;
   for j:=len downto 1 do
    begin
    k:=c[j];
    c[j]:=(k+ys*10) div i;
    ys:=(k+ys*10) mod i;
   end;
   while c[len]=0 do dec(len);
  end;
  rewrite(output);
  for i:=len downto 1 do write(c[i]);
  writeln;
  close(output)
end.