Question

The following function is Tech() is a part of some class which is used to check if a given number is a Tech number or not. There are some places in the code marked by ?1?, ?2?, ?3? which may be replaced by a statement / expression so that the function works properly. 

A number is Tech number if the count of digits is even and the square of the sum of its two equal halves is equal to the number itself.

Example: 2025 = 20 + 25 = (45)² = 2025

boolean isTech(int n)

{

  String s = String.valueOf(n);

  int len = ?1?;

  if (len %2!= 0)

  return ?2?:

  intfirst = Integer.parselnt(s.substring(0, len/2));

  int second = Integer.parseInt(s.substring(len/2));

  int sum =first + second;

  return ?3? == n;

}

What are the expressions or statements at?1?, ?2? and ?3?

Answer 1

To make the isTech() function work correctly based on the logic of a Tech number, the placeholders should be replaced as follows:

• ?1? : s.length()
  This calculates the total number of digits in the number by getting the length of the string s.
• ?2? : false
  A Tech number must have an even count of digits. If the length is odd (len % 2 != 0), it immediately fails the condition, so the function returns false.
• ?3? : sum * sum (or Math.pow(sum, 2))
  The final step checks if the square of the sum of the two halves is equal to the original number n.