Java实现 洛谷 P1426 小鱼会有危险吗

import java.util.LinkedList;
import java.util.Scanner;

public class Main {
	private static Scanner cin;
	private static LinkedList<String> list;
	private static int initSpeed = 7;
	private static double percent = 0.98;
	private static int x = 0;
	private static int s = 0;

	public static void main(String args[]) throws Exception {
		cin = new Scanner(System.in);
		s = cin.nextInt();
		x = cin.nextInt();
		calc(0,initSpeed);
	}

	public static void calc(double distanceOver, double curSpeed) {
		//首先判断是否已进入检测范围
		if(distanceOver > (s-x)) {
			if((distanceOver +curSpeed)<=s+x) {
				System.out.println("y");
				return;
			}else {
				System.out.println("n");
				return;
			}
		}
		//检测走一步后是否进入检测范围
		if((distanceOver +curSpeed) > (s-x)) {
			if((distanceOver +curSpeed*(1+percent))<=s+x) {
				System.out.println("y");
				return;
			}else {
				System.out.println("n");
				return;
			}
		}else {
			calc((distanceOver+curSpeed),curSpeed*percent);
		}
	}

}