Sum Problem

http://acm.hdu.edu.cn/showproblem.php?pid=1001

Sum Problem Time Limit: 1000/500 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others) Total Submission(s): 606504    Accepted Submission(s): 153369   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     Author DOOM III

#include<stdio.h>

int main()
{
	int n,sum;
	while(scanf("%d",&n)!=EOF)
	{
		sum=0;
		while(n)
		{
			sum+=n;
			n--;
		}
		printf("%d\n\n",sum);
	}
	return 0;
}