用C实现求阶乘之和
昨天师父给的任务,让写一个多线程计算一个1000以内输入数的阶乘和的小程序。我用C语言来实现,过程都是自己想出来的,中间出过在用循环的时候采用unsigned类型判断出错的问题。以下是该程序的实现,这里只是先把过程写出来,还没有用到多线程……
// methods.c#include <stdio.h>long double Fn(int n);int main(void){ long double sum = 0; int i, n; i = n = 0; printf("Please input a number: \n"); scanf("%d", &n); if (n > 1000 )printf("ERROR!The number is too large!\nPlease try again!(0~1000)\n"); else if (n < 0)printf("ERROR!The number is invalid!\nPlease try again!(0~1000)\n"); else {for (i = 0; i <= n; i++) sum += Fn(i);printf("The %d factorial's sum is %Lf\n", n, sum); } return 0;}long double Fn(int n){ if (n == 0)return 1; return Fn(n - 1) * n;}
利用多线程的实现,我会在月底之前写出来。
以下是执行结果:
http://dl.iteye.com/upload/attachment/0068/6477/6c1a6fe5-6716-38ec-8271-99bbb98acd29.png
页:
[1]