.使用函数编写程序求n!(n!=1*2*3*4*......*n)

#include <stdio.h>

// 求n的阶乘
int factorial(int n) {
    int result = 1;
    for (int i = 1; i <= n; i++) {
        result *= i;
    }
    return result;
}

int main() {
    int n = 0, sum = 0;
    printf("请输入n值：\n");
    scanf("%d", &n);
    for (int j = 1; j <= n; j++) {
        sum += factorial(j);
    }
    printf("%d", sum);
    return 0;
}