Fraction pairs with sum 1

class Solution {
    
    
    public static int gcd(int a, int b)
    {
        if(b == 0)
        {
            
            return a;
        }
        
        return gcd(b, a%b);
    }

    
    
    
    public static int countFractions(int n, int[] numerator, int[] denominator) 
    {
        // code here'''''
        
                
        int count=0;
        HashMap<Double,Integer> map = new HashMap<>();
        
        for(int i=0; i<n; i++) 
        {
            
            
            double fraction = (double)numerator[i]/(double)denominator[i];
            
            double m = (double)(denominator[i]-numerator[i])/denominator[i];
            
            count += map.getOrDefault(m, 0);
            
            map.put(fraction, map.getOrDefault(fraction, 0) + 1);
        }
        
        
        return count;

        
        
        
        
        
    }
}