[국비지원과정16] JAVA - 등차수열 알고리즘

package loop;

import java.util.Random;

public class Ex08 {
public static void main(String[] args) {
	
	Random ran = new Random();
	int begin = ran.nextInt(10)+1;
	int end = ran.nextInt(10)+100;
	
	System.out.println("begin : %d, end : %d\n, begin , end");
	
	// 두 정수의 합계 구하기
	int total = 0;
	int n1 = begin;
	while(n1 <= end) {
		total += n1;
		n1++;
	}
	System.out.println("total : " + total);

	
	//등차수열의 합
	int sum = (begin + end)*(end-begin+1)/ 2;
	System.out.println("sum : "+ sum);
	
}
}