AC代码

#include <iostream>
#include <cmath>
double meter = 7 , s , a , l , r , now = 0;
using namespace std;
bool tcstsf(double s , double a){    
    l=s-a;                  
	r=s+a;                   
	for(;;)                 
	{
		if (now>r)         
		{
			cout<<'n';       
			return 0;        
		}
		if (l<=now&&now<=r)  
		{
			if (now+meter>r) 
			{   
				return true; 
			}
			else          
			{; 
				return false;  
			}
		}
		now+=meter;         
		meter*=0.98;   
	}
}
int main(){
    cin >> s >> a;
    bool isDangerous = tcstsf(s, a); 
    if (!isDangerous) { 
        cout << "y";
    } else { 
        cout << "n";
    }
    return 0;
}