ACM：1001 Sum Problem 求和问题 Java代码

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.

计算一连串整数的累积和

Input

The input will consist of a series of integers n, one integer per line.

输入由一系列的整数组成，每行接受一个整数输入(代表 n)

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.

对于每一种情况，SUM在空白行之后的单独的一行输出。假定所有的结果都在有符号的32位整型范围之内

Sample Input

1

100

Sample Output

1

5050

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");  
}  
}