fact.pas

pascal的编译器 交作业没问题

//求1*2*3*...*x.

read x; 
if x<17 then   //防止数太大,溢出
   if 0 < x then
      fact := 1;
      repeat
        fact := fact * x;
        x := x - 1
      until x = 0;
      write fact
   end
else
   write 0
end