题解 | #小球走过路程计算#

import java.util.Scanner;

public class Main {
  public static void main(String[] args) {
    Scanner scanner = new Scanner(System.in);
    float h = scanner.nextFloat();
    int n = scanner.nextInt();

    // 每一次回弹后高度除2
    double height = h /  Math.pow(2, n);
    // 简单的等比数列求和
    // 需要注意 除第一次下落 所有下落都会进行两倍的路程
    double heightSumHalf = h / 2 * (1 - Math.pow(0.5, n - 1)) / (1 - 0.5);
    double heightSum = heightSumHalf * 2 + h;

    System.out.println(String.format("%.3f", height) + " " + String.format("%.3f",
                       heightSum));
    //输出格式为：System.out.println(String.format("%.3f", h)+" "+String.format("%.3f", sum));
  }
}