Question

C语言S=1+1!+2!+3!+...+N! 要求N从命令行输入,且1<=N<=10利用递归实现。F(N)=1,N=1; F(N)=N*F(N-1), N>1？

Answer 1

#include <stdio.h>

unsigned long f(int n)

{

    if(n<2)

        return 1UL;

    return n*f(n-1);

}

int main()

{

    int n,i;

    unsigned long sum;

    scanf("%d",&n);

    for(i=1,sum=0;i<=n;++i)

        sum+=f(i);

    printf("%lu\n",sum);

    return 0;

}

Answer 2

很简单的函数和循环