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！