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

簡述一下哈，最近真是無聊，真是沒事干，所以打算每天抽出幾個小時來做做題，正直七夕哈，祝大家有情人終成眷屬，表白的都成功，我打算敲一天代碼，new一天對象，??O(∩_∩)O哈哈~

當(dāng)然這是最簡單的一道題啦，所以我就不說思路咯，說一下用java A題的應(yīng)該注意的事項：

1.必須要導(dǎo)包，千萬不能忘記了

2.類名必須為Main

3.要注意輸入、輸出的格式

代碼：

import java.util.Scanner;

public class Main1001 {
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        int result = 0;
        while (in.hasNextInt()) {
            int a = in.nextInt();
            for (int i = 1; i <= a; i++) {
                result = result + i;
            }
            System.out.println(result);
            System.out.println();
            result = 0;
        }
    }
}