마지막 두 원소 (Arrays.copyOf)

내풀이

import java.util.*;

class Solution {
    public int[] solution(int[] num_list) {
        int[] answer = Arrays.copyOf(num_list,num_list.length+1);

        int lastInt = answer[num_list.length-1];
        int secondInt = answer[num_list.length-2];

        int addInt = lastInt > secondInt ? lastInt-secondInt : lastInt*2;
        
        answer[num_list.length] = addInt;
        
        return answer;
    }
}

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