프로그래머스 level1 : 정수 제곱근 판별 - Java

import java.lang.Math;
class Solution {
    public long solution(long n) {
        long answer = 0;
        double result = Math.sqrt(n);
        if(result % 1 != 0) answer = -1;
        else answer = ((long)result+1)*((long)result+1);
        return answer;
    }
}