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
  

answer：
import java.util.Scanner; public class Main{ public static void main(String[] args) { Scanner scan = new Scanner(System.in); long i,sum,n; while(scan.hasNextLong()) { n = scan.nextLong(); sum = 0; for(i=1; i<=n;i++) { sum = sum+i; } System.out.println(sum); System.out.print("\r\n"); } }

注意点：最后一行的空格要写成：\r\n，windows中的空格就是这样！