다음에 올 숫자

/* 다음에 올 숫자

 * 등차수열 혹은 등비수열 common이 매개변수로 주어질 때,

 * 마지막 원소 다음으로 올 숫자를 return

 *

 * common       result

 * [1, 2, 3, 4] 5

 * [2, 4, 8]    16

 */

 

public class programmer_0_2 {
    static int[] input1 = {1,2,3,4};
    static int[] input2 = {2,4,8};       
    static int[] input3 = {-60,0,60};       
    
    public int solution(int[] common) {
        int answer = 0;
        int inputAr = common.length;
        
        if(common[1] - common[0] == common[2] - common[1]){
            answer = common[common.length-1] + (common[1] - common[0]);
        } else 
            answer = common[common.length-1] * (common[1]/common[0]);
        
        return answer;
    }
    public static void main(String[] args){
        programmer_0_2 t = new programmer_0_2();
        
        System.out.println("result = " + t.solution(input1));
        System.out.println("---------------------------------------");
        System.out.println("result2 = " + t.solution(input2));
        System.out.println("---------------------------------------");
        System.out.println("result3 = " + t.solution(input3));
        System.out.println("---------------------------------------");
    }
}