[프로그래머스/Java] 다음에 올 숫자

-Code

class Solution {
    public int solution(int[] common) {
        int len = common.length - 1;
        if (len == 1) return common[1] * 2 - common[0];
        
        int[] gaps = new int[2];

        for (int i = 1; i < 3; i++) {
            gaps[i - 1] = common[i] - common[i - 1];
        }
        
        if (gaps[0] == gaps[1]) {
            return common[len] + gaps[0];
        }
        return common[len] * (gaps[1] / gaps[0]);
    }
}