编程求E1+E2+…+E100的值​

题目：编程求1+2+…+100的值。

package chap3_方法;

/**
 * 编程求E1+E2+E3+……+E100的值
 * 1 + 1+2 + 1+2+3 +……+ 1+2+……+100
 */

public class Test10 {
    public static void main(String[] args) {
        int sum_i = 0;
        for (int i = 1; i <= 100; i++) {
            int sum_j = 0;
            for (int j = 1;j<=i;j++){
                sum_j += j;
            }
            sum_i += sum_j;
        }
        System.out.println(sum_i);//171700
    }
}