LeetCode | 0914. X of a Kind in a Deck of Cards卡牌分组【Python】

LeetCode 0914. X of a Kind in a Deck of Cards卡牌分组【Easy】【Python】【数学】

Problem

LeetCode

In a deck of cards, each card has an integer written on it.

Return true if and only if you can choose X >= 2 such that it is possible to split the entire deck into 1 or more groups of cards, where:

  • Each group has exactly X cards.
  • All the cards in each group have the same integer.

Example 1:

Input: deck = [1,2,3,4,4,3,2,1]
Output: true
Explanation: Possible partition [1,1],[2,2],[3,3],[4,4].

Example 2:

Input: deck = [1,1,1,2,2,2,3,3]
Output: false´
Explanation: No possible partition.

Example 3:

Input: deck = [1]
Output: false
Explanation: No possible partition.

Example 4:

Input: deck = [1,1]
Output: true
Explanation: Possible partition [1,1].

Example 5:

Input: deck = [1,1,2,2,2,2]
Output: true
Explanation: Possible partition [1,1],[2,2],[2,2].

Constraints:

  • 1 <= deck.length <= 10^4
  • 0 <= deck[i] < 10^4

问题

力扣

给定一副牌,每张牌上都写着一个整数。

此时,你需要选定一个数字 X,使我们可以将整副牌按下述规则分成 1 组或更多组:

  • 每组都有 X 张牌。
  • 组内所有的牌上都写着相同的整数。

仅当你可选的 X >= 2 时返回 true。

示例 1:

输入:[1,2,3,4,4,3,2,1]
输出:true
解释:可行的分组是 [1,1],[2,2],[3,3],[4,4]

示例 2:

输入:[1,1,1,2,2,2,3,3]
输出:false
解释:没有满足要求的分组。

示例 3:

输入:[1]
输出:false
解释:没有满足要求的分组。

示例 4:

输入:[1,1]
输出:true
解释:可行的分组是 [1,1]

示例 5:

输入:[1,1,2,2,2,2]
输出:true
解释:可行的分组是 [1,1],[2,2],[2,2]

提示:

  • 1 <= deck.length <= 10^4
  • 0 <= deck[i] < 10^4

思路

数学

直接调用 Python 的 collections 库,Counter 统计。
然后计算所有整数出现次数的最大公约数。
Python3代码
from typing import List
import collections
import math

class Solution:
    def hasGroupsSizeX(self, deck: List[int]) -> bool:
        # Counter统计出来是一个字典
        c = list(collections.Counter(deck).values())
        res = c[0]
        # 求所有数的最大公约数
        for x in c:
            res = math.gcd(res, x)
        return res > 1

GitHub链接

Python

posted @ 2020-03-27 16:35  Wonz  阅读(146)  评论(0编辑  收藏  举报