HDU_oj_1001 Sum Problem

Problem 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

 

分析：

注意点：

数据输出后多加一行空白行

 

#include<iostream>
using namespace std;
int main()
{
    int num;
    int sum=0;
    while(cin>>num)
    {
        for(int i=1;i<=num;i++)
        sum+=i;
        cout<<sum<<endl<<endl;
        sum=0;
    }
    return 0;
}