Caculate 1!+2!+...+n! Input: An integer for n. Output: An interger for the result.c语言实现

以下是C语言实现：

#include <stdio.h>

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

int main() {
    int n;
    printf("Enter a positive integer: ");
    scanf("%d", &n);
    int sum = 0;
    for (int i = 1; i <= n; i++) {
        sum += factorial(i);
    }
    printf("The sum of factorials from 1 to %d is %d\n", n, sum);
    return 0;
}

首先定义了一个计算阶乘的函数`factorial()`，然后在主函数中循环计算1到n的阶乘并求和，最终输出结果。