1-n阶乘之和（两种方式）

#include<stdio.h>

int main() {
  int n = 0;
  printf("请输入一个正整数：");
  scanf_s("%d", &n);
  int all = 0;
  int sun = 0;
  for (int i = 1; i < n+1; i++) {
    for (int j = 1,sum=1; j < i+1; j++) {
      sum = j * sum;
      sun = sum;
    }
    all = all + sun;
  }
  printf("1-%d的阶乘之和为：%d", n, all);
  return 0;
}

#include<stdio.h>

int main() {
  int n = 0;
  printf("请输入一个正整数：");
  scanf_s("%d", &n);
  int all = 0;
  int sum = 1;
  for (int i = 1; i < n+1; i++) {
    sum = sum * i;
    all = all + sum;
  }
  printf("1-%d的阶乘之和为：%d", n, all);
  return 0;
}