在两个数字中寻找共享数字的麻烦

Question

I need to check whether two numbers have some shared digits. My method here doesn't return anything when tested.

What I'm trying to do here is to get each digit of the first number, then loop through the second number to try finding another digit that is equal to the first one. If so, I want to return true and if not I want to keep checking.

    public static boolean hasSharedDigit(int num1, int num2) {
        int digit1, digit2;
        boolean isShared;
        boolean isNum1TwoDigits = ((num1 >= 10) && (num1 <= 99)) ? true : false;
        boolean isNum2TwoDigits = ((num2 >= 10) && (num2 <= 99)) ? true : false;
        if ((!isNum1TwoDigits) || (!isNum2TwoDigits))
            return false;
        while (num1 > 10) {
            digit1 = num1 % 10;
             while (num2 > 10) {
                digit2 = num2 % 10;
                if (digit2 == digit1)
                    return true;
             }
             num1 /= 10;
        }
        return false;

    }

Answer 1

Probably not the most efficient method, but you could create a Set containing the digits of which each number is composed and then check that the intersection is not empty.

public static Set<Integer> getDigits(int num)
{
  Set<Integer> result = new TreeSet<Integer>();

  if (num == 0)
    result.add(0);
  else
  {
    num = Math.abs(num);
    while (num > 0)
    {
      result.add(num % 10);
      num /= 10;
    }
  }

  return (result);

} // getDigits

public static boolean hasSharedDigit(int num1, int num2)
{
  Set<Integer> digits1 = getDigits(num1);
  Set<Integer> digits2 = getDigits(num2);
  digits1.retainAll(digits2);
  return (!digits1.isEmpty());
}

Answer 2

Here is a basic solution that converts the numbers to arrays of characters and compares them in two for loops

public static boolean hasSharedDigit(int num1, int num2) {
    if (num1 == num2) {
        return true;
    }

    char[] arr1 = String.valueOf(num1).toCharArray();
    char[] arr2 = String.valueOf(num2).toCharArray();

    for (char ch1 : arr1) {
        for (char ch2 : arr2) {
            if (ch1 == ch2) {
                return true;
            }
        }
    }
    return false;
}