[Programmers] 정수 제곱근 판별

#include <cmath> // for : Use sqrt()

long long solution(long long n) {
    long long answer = 0;
    int ans = sqrt(n);
    if( ans * ans == n )
        answer = (ans+1) * (ans+1);
    else
        answer = -1;   
    return answer;
}