Sum Problem

题目—from hdoj

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

分析

程序

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