gistfile1.txt

func findPairs(ar: [Int], pairs: Int) -> Int {
    
    var res = pairs
    
    if ar.count > 0 {

        var newAr = ar

        let sock = newAr.remove(at: 0)

        for (index, element) in newAr.enumerated() {
        
            if element == sock {
                
                newAr.remove(at: index)
                res += 1
                break
            }
        }
        
        return findPairs(ar: newAr, pairs: res)
    }
    
    return res
}