Daily Challenge #195 - No Zeroes for Heroes

Setup

It has officially been decided that numbers that end with zeroes are boring. They might be fun in your world, but definitely not here. Implement a function to eradicate any trailing zeroes. If the given number is 0, just leave him alone. Poor guy anyway.

Examples

1450 -> 145
960000 -> 96
1050 -> 105
-1050 -> -105

Tests

9070
210000
10210
0

---

This challenge comes from thecodix on CodeWars. Thank you to CodeWars, who has licensed redistribution of this challenge under the 2-Clause BSD License!

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Comments

[Corentin Leffy]

A Dart solution using TDD :

void main() {
  group("Eradicate trailing zeroes :", () {
    final zeroesToHeroes = {
      1450: 145,
      960000: 96,
      1050: 105,
      -1050: -105,
      9070: 907,
      210000: 21,
      10210: 1021,
      0: 0
    };
    zeroesToHeroes.forEach((zero, hero) {
      test("$zero should become $hero", () {
        expect(eradicateTrailingZeroes(zero), equals(hero));
      });
    });
  });
}

num eradicateTrailingZeroes(num number) {
  for (; (number % 10 == 0) ^ (number == 0); number /= 10) {}
  return number;
}

[SavagePixie]

Elixir

Elixir with recursion:

def dezerofy(0), do: 0
def dezerofy(n), do: _dezerofy(n, rem(n, 10))
defp _dezerofy(n, 0), do: _dezerofy(div(n, 10), rem(n, 100))
defp _dezerofy(n, _), do: n

Elixir without recursion, inspired by @avalander 's solution:

def dezerofy(0), do: 0
def dezerofy(n), do: n
  |> Integer.digits
  |> Enum.reverse
  |> Enum.drop_while(&(&1 == 0))
  |> Enum.reverse
  |> Integer.undigits

[Rohit Prasad]

Python

var = int(input("Enter the number: "))

while var != 0:
        if var%10 == 0:
                var = var/10
        else:
                break
print(int(var))

[Nijeesh Joshy]

Ruby

Regex

# using strings
def remove_trailing_zeros(number)
  number
    .to_s
    .gsub(/0{1,}$/,"")
    .to_i || 0
end

Recursion

def remove_trailing_zeros(number)
  return 0 if number == 0
  return remove_trailing_zeros(number / 10) if number % 10 == 0
  return number
end

TESTS

require "test/unit"


class RemoveTrailingZerosTest < Test::Unit::TestCase
  def test_remove_trailing_zeros
    assert_equal 907, remove_trailing_zeros(9070)
    assert_equal 21, remove_trailing_zeros(210000)
    assert_equal 1021, remove_trailing_zeros(10210)
    assert_equal 0, remove_trailing_zeros(0)
  end
end

[Craig McIlwrath]

Recursive Haskell solution

eradicateTrailingZeroes :: (Integral a) => a -> a
eradicateTrailingZeroes 0 = 0
eradicateTrailingZeroes n
  | n `rem` 10 == 0 = eradicateTrailingZeroes $ n `quot` 10
  | otherwise       = n

[Avalander]

Does this work when passing 0 as argument?

[Craig McIlwrath]

Good catch, guess I missed that case. Updated it.

[matej]

Java with recursion

public int cutZeroes(int i) {
   return i == 0 || i%10 != 0 ? i : cutZeroes(i/10);
}

[Alexander Weleczka]

Felt like a bit of recursion is always fun to do.
And I couldn't remember when I used extensions in C# last...

public static int StripTrailingZeros(this int input)
{
    if(input != 0 && input % 10 == 0)
    {
        return (input / 10).StripTrailingZeros();
    }

    return input;
}

Project on GitHub

[Alexander Weleczka]

Test Run Successful.
Total tests: 9
     Passed: 9
Total time: 1.6941 Seconds

[Cent]

Javascript

const removeTrailingZeros = (number) => {
  if (number === 0) return number;
  if (number%10 === 0 ) removeTrailingZeros(number/10);
  else return number;
}

I just realized the function returns undefined when it's not 0 so let me try to fix that real quick lol

const removeTrailingZeros = (number) => {
  while(number % 10 === 0 && number !== 0) {
    number= number / 10;
  }
  return number;
}

codepen

Can someone tell my why the recursion I tried to do didn't work?

[Vidit Sarkar]

I guess you just need to add a 'return' in front of

removeTrailingZeros(number/10)

The code will be--

const removeTrailingZeros = (number) => {
  if (number === 0) return number;
  if (number%10 === 0 ) return removeTrailingZeros(number/10);
  else return number;
}

[Cent]

Yep, that does it. Thanks!

[Ryan J]

Javascript

function removeLast0(input) {
    if (input === 0) return 0;
    if (input % 10 === 0) return removeLast0(input / 10);
    return input;
}

[Lucas Frigo de Souza]

C#

        static void Main(string[] args)
        {
            System.Console.WriteLine("No Zero Challenge");
            Console.WriteLine(Eradicate(1450));   //145
            Console.WriteLine(Eradicate(960000)); //96
            Console.WriteLine(Eradicate(1050));   //105
            Console.WriteLine(Eradicate(-1050));  //-105
            Console.WriteLine(Eradicate(9070));   //907
            Console.WriteLine(Eradicate(210000)); //21
            Console.WriteLine(Eradicate(10210));  //1021
            Console.WriteLine(Eradicate(0));      //0
            Console.WriteLine(Eradicate(1234));   //1234
        }

        public static int Eradicate(int number)
        {
            if (number == 0) return number;
            while(number.ToString()[^1] == '0')
                number /= 10;
            return number;
        }

[Lucas Frigo de Souza]

and Dart

void main() {
  print(eradicate(1450));   //145
  print(eradicate(960000)); //96
  print(eradicate(1050));   //105
  print(eradicate(-1050));  //-105
  print(eradicate(9070));   //907
  print(eradicate(210000)); //21
  print(eradicate(10210));  //1021
  print(eradicate(0));      //10
  print(eradicate(1234));   //1234
}

double eradicate (double number){
  if(number == 0) return number;

  while(number.remainder(10) == 0)
    number /= 10;

  return number;
}