Question

Complete the method, isPerfectSquare(). The method takes in a positive integer, n. It returns a boolean that is true if n is a perfect square, false otherwise. A perfect square is an integer whose square root is also an integer. You may assume that n is a positive integer.
Hint: find the square root of n, cast it to an int value, then square it and compare this square to n.
Starter code:-
public class Square {
public static boolean isPerfectSquare(int n) {
//TODO: complete this method
}
}

Answer 1

Answer:

1. public class Square {
2.    public static boolean isPerfectSquare(int n){
3.        int sqrt_n = (int) Math.sqrt(n);
4.        if(sqrt_n * sqrt_n == n ){
5.            return true;
6.        }else{
7.            return false;
8.        }
9.    }
10. }

Explanation:

Firstly, use sqrt method from Math package to calculate the square root of input n (Line 3). Cast the result to integer and assign it to sqrt_n variable.

Next, square the sqrt_n and check if it is equal to input n (Line 4). If so, return true, if not, return false (Line 4-8).