如题，找不到错在哪了，求指点QAQ

题目：P1426

以下是我的代码：

#include<iostream>
using namespace std;

int main() {
	double s, x;
	double speed = 7;
	cin >> s >> x;
	int d = 0;
	while (d < s + x) {
		d += speed;
		
		if (d >= s - x && d + speed * 0.98 > s + x) {
			cout << "n" << endl;
			break;
		}
		else if (d >= s - x && d + speed * 0.98 <= s + x) {
			cout << "y" << endl;
			break;
		}
		speed *= 0.98;
	}

	return 0;
}