每日一练ACM 2019.04.14

2019.4.14

第1001题：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

解：

package Acm;

import java.util.Scanner;

public class test1 {
    public static void main(String[] args)
    {
        Scanner input=new Scanner(System.in);
        int a;
        int b;
        int sum = 0;
        while(input.hasNext())
        {
            a=input.nextInt();
            for(int i=1;i<=a;i++){
                sum=sum+i;

            }

            System.out.println(sum);
            //System.out.println();
            sum=0;
        }

    }

}