Sum Problem

Time Limit: 1000/500 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others) Total Submission(s): 223816    Accepted Submission(s): 54902

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

 

思路：

 

代码:

#include <stdio.h>

#include <stdlib.h>

int

main

()

{

    int n

,sum

=

0

,i

;

    while

(scanf

(

"%d"

,&n

)!=EOF

)

    {

      for

(i

=

1

;i

<=n

;i

++)

      sum

=sum

+i

;

      printf

(

"%d\n\n"

,sum

);

      sum

=

0

;

      }

}