Check whether the given number is a perfect square

Objec­tive:  Given an integer check whether it is a perfect square.

Example:

number = 37
Output: false

number = 49
Output: true

This is fun puzzle which is asked in the interview.
Approach:

1. Say number is n.
2. Start a loop from 1 to n/2.
3. During iteration, for every integer ‘i’, calculate x = i*i.
4. Now with this ‘x’ there are 3 possibilities.
   1. If x == n then n is a perfect square, return true
   2. If x > n then x has crossed the n, n is not perfect square. Return false
   3. If above step a or b are not true then continue.

Time Complexity: O(sqrt(n))

Code: Run Code

Output:

37 is square: false
49 is square: true