[プログラマー/python]ハッシュ-偽装

🤓 に答える

def solution(clothes):
    answer = {}
    # {'headgear': 2, 'eyewear': 1}
    for i in clothes:
        if i[1] in answer: 
            answer[i[1]] += 1
        else: 
            answer[i[1]] = 1
    cnt = 1
    for i in answer.values():
        cnt *= (i+1)
    return cnt - 1

👩🏻‍🏫 別の解釈

def solution(clothes):
    from collections import Counter
    from functools import reduce
    # Counter({'headgear': 2, 'eyewear': 1})
    cnt = Counter([kind for name, kind in clothes])
    answer = reduce(lambda x, y: x*(y+1), cnt.values(), 1) - 1
    return answer

▼Python文法

Counter(~)

from collections import Counter

list = ['kim', 'kim', 'park', 'choi', 'kim', 'kim', 'kim', 'choi', 'park', 'choi']
result = collections.Counter(list) 
print(result) # Counter({'kim': 5, 'choi': 3, 'park': 2})

reduce

lambda

from functools import reduce
result = reduce(lambda x, y: x + y, [0, 1, 2, 3, 4])
print(result) # 10