杭电ACM1001

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

 #include <stdio.h>

 int main(void)
 {
     int i,n,sum;
     sum = ;
     while(scanf("%d",&n)!=EOF)
     {
         sum=;
         for (i=;i<=n;i++)
             sum+=i;
         printf("%d\n\n",sum);
     }
     return ;
 }

Sum Problem

Time Limit: 1000/500 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others)
Total Submission(s): 416900    Accepted Submission(s): 105068

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