solved 'Bricks Game' on hackerrank https://www.hackerrank.com/challenges/play-game

play_bricks_dp.py

def max_score(bricks):
    """bricks: A list of bricks."""
    sz = len(bricks)
    # DP algorithm. See the editorial.
    # https://www.hackerrank.com/challenges/play-game/editorial
    max_score_from = [0] * sz
    max_score_from[-1] = bricks[-1]
    max_score_from[-2] = max_score_from[-1] + bricks[-2]
    max_score_from[-3] = max_score_from[-2] + bricks[-3]

    backward_sum = max_score_from[:]
    for i in range(sz - 4, -1, -1):
        # Calculate scores with different actions: take 1, 2 or 3 bricks.
        score_take_one = bricks[i] + \
            backward_sum[i + 1] - max_score_from[i + 1]
        score_take_two = bricks[i] + bricks[i + 1] + \
            backward_sum[i + 2] - max_score_from[i + 2]
        score_take_three = bricks[i] + bricks[i + 1] + bricks[i + 2] + \
            backward_sum[i + 3] - max_score_from[i + 3]

        max_score_from[i] = max(
            score_take_one, score_take_two, score_take_three)
        backward_sum[i] = backward_sum[i + 1] + bricks[i]

    return max_score_from[0]


test_case_num = int(raw_input())
for _ in range(test_case_num):
    raw_input()
    bricks = map(int, raw_input().split())
    print max_score(bricks)