004 Find the nth Digit of a Number

Instructions:

Description

Complete the function that takes two numbers as input, num and nth and return the nth digit of num (counting from right to left).

Note

• If num is negative, ignore its sign and treat it as a positive value
• If nth is not positive, return 1
• Keep in mind that 42 = 00042. This means that findDigit(42, 5) would return 0

Examples

findDigit(5673, 4)     returns 5
findDigit(129, 2)      returns 2
findDigit(-2825, 3)    returns 8
findDigit(-456, 4)     returns 0
findDigit(0, 20)       returns 0
findDigit(65, 0)       returns -1
findDigit(24, -8)      returns -1

TryCode:

func findDigit(_ num:Int, _ nth: Int) -> Int {
    var numToString = "\\(num)"
    if nth <= 0 {
        return -1
    }else{
        if numToString.count >= nth{
            var offsetNumber = nth
            offsetNumber.negate()
            offsetNumber + 1
            return
            Int("\\(numToString[numToString.index(numToString.endIndex, offsetBy: offsetNumber)])" ) ?? 0
        }else{
        return  0
        }
    }
}

BetterCode:

func findDigit(_ num: Int, _ nth: Int) -> Int {
  let positive = abs(num)
  
  guard nth > 0 else { return -1 }
  guard positive > 0 else { return 0 }
  guard nth > 1 else { return positive % 10 }
  
  return findDigit(positive / 10, nth - 1)
}