c 语言练习__求到N的阶乘的和。

#include <stdio.h>

/* 题目如下
 * S = 1 + 2! + 3! + ... + N!
 */
int main(int argc, char *argv[])
{
    int s = ;
    int n = ;
    int i = ;
    int m = ;

    printf("Please input N :");
    if (scanf("%d",&n) ==  ){
        while (i <= n ){
            m *= i++;
            s += m;
        }
        printf("The result is %d \n", s);

    }
    else
        printf("Input Error.\n");

    return ;
}