HDOJ 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

 

Codes:

#include <stdio.h>
main()
{
    int a,i,sum;
    
    while(scanf("%d",&a)!=EOF)
    {
        sum=0;
        for(i=1;i<=a;i++)
            sum=sum+i;
        printf("%d\n\n",sum);
    }
}