[프로그래머스] 정수 제곱근

class Solution {
    public double solution(double n) {
        double answer = 0;
        double sqrtNumber = Math.sqrt(n);
        
        if(n%sqrtNumber == 0){
            answer= Math.pow(sqrtNumber+1, 2);
        }else{
            answer = -1;
        }
        return answer;
    }
}