題解 | #牛牛的西格瑪#
牛牛的西格瑪
http://fangfengwang8.cn/practice/c6b750ee8853484f8dbf14b9531b501f
#include<stdio.h> int sum(int n) { if (n==1) return 1; else return n + sum(n - 1); } int main() { int n = 0; scanf("%d", &n); printf("%d\n", sum(n)); return 0; }