sum of all integer numbers
时间限制:1000 ms | 内存限制:65535 KB
难度:0
- 描述
- Your task is to find the sum of all integer numbers lying between 1 and N inclusive.
- 输入
- There are multiple test cases.
The input consists of a single integer N that is not greater than 10000 by it's absolute value. - 输出
- Write a single integer number that is the sum of all integer numbers lying between 1 and N inclusive.
- 样例输入
-
3
- 样例输出
-
6
View Code#include<stdio.h> int main() { int n; while(scanf("%d",&n)!=EOF) { if(n>0)printf("%d\n",n*(n+1)/2); if(n<=0) { n=-n;printf("%d\n",-n*(n+1)/2+1); } } return 0; }
- 来源