문제 링크

정답 :

def solution(arr, n):
    if len(arr) % 2 == 0:
        arr[1::2] = [i + n for i in arr[1::2]]
    else:
        arr[::2] = [i + n for i in arr[::2]]
    
    return arr

방법 1:

def solution(arr, n):
    if len(arr) % 2:
        for i in range(0, len(arr), 2):
            arr[i] += n
    else:
        for i in range(1, len(arr), 2):
            arr[i] += n

    return arr