Winter-1-B Sum 解题报告及测试数据

Time Limit:500MS     

Memory Limit:32768KB

Description

​Hey, welcome to HDOJ(Hangzhou Dianzi University Online Judge).In this problem, your task is to calculate SUM(n) = 1 + 2 + 3 + ... + n.

Input

The input will consist of a series of integers n, one integer per line.

Output

​For each case, output SUM(n) in one line, followed by a blank line. You may assume the result will be in the range of 32-bit signed integer.

Sample Input

1

100

Sample Output

1

5050 

以下是代码：

#include <cstdio>
using  namespace std;
int  main(){
    int  n,sum;
    while ( scanf ( "%d" ,&n)!=EOF){
        sum=0;
        for ( int  i=1;i<=n;i++)sum+=i;
        printf ( "%d\n\n" ,sum);
    }
}