[프로그래머스] 체육복 (42862, 파이썬)

def solution(n, lost, reserve):
    lost_set = set(lost)
    reserve_set = set(reserve)
    reserve_and_lost = lost_set & reserve_set

    lost_set -= reserve_and_lost
    reserve_set -= reserve_and_lost

    for i in reserve_set:
        if i - 1 in lost_set:
            lost_set -= {i - 1, }
        elif i + 1 in lost_set:
            lost_set -= {i + 1, }

    return n - len(lost_set)