【leetcode】1079. Letter Tile Possibilities

本文转载自查看原文 2019-06-15 06:00 559 python/ leetcode

题目如下：

You have a set of tiles, where each tile has one letter tiles[i]printed on it. Return the number of possible non-empty sequences of letters you can make.

Example 1:
Input: "AAB"
Output: 8 Explanation: The possible sequences are "A", "B", "AA", "AB", "BA", "AAB", "ABA", "BAA". 
Example 2:
Input: "AAABBC"
Output: 188 
Note:

1 <= tiles.length <= 7

tiles consists of uppercase English letters.

解题思路：tiles的最大长度是7，那么理论上最多有7!种组合，这个数量非常小，可以全排列所有的的可能性然后过滤重复的数据。

代码如下：

class Solution(object):
    def numTilePossibilities(self, tiles):
        """
        :type tiles: str
        :rtype: int
        """
        import itertools
        l = range(len(tiles))
        dic = {}
        for i in range(1,len(l) + 1):
            for j in itertools.permutations(l, i):
                v = ''
                for k in j:
                    v += tiles[k]
                if v not in dic:dic[v] = 1
        return len(dic)

免责声明！

本站转载的文章为个人学习借鉴使用，本站对版权不负任何法律责任。如果侵犯了您的隐私权益，请联系本站邮箱yoyou2525@163.com删除。

猜您在找 leetcode 1079 Letter Tile Possibilities [Swift]LeetCode1079. 活字印刷 | Letter Tile Possibilities [LeetCode] Letter Combinations of a Phone Number LeetCode:Letter Combinations of a Phone Number 【LeetCode】17. Letter Combinations of a Phone Number LeetCode(17) － Letter Combinations of a Phone Number [leetcode]Letter Combinations of a Phone Number @ Python Letter Combinations of a Phone Number leetcode java [LeetCode] Letter Case Permutation 字母大小写全排列 [LeetCode] 17. Letter Combinations of a Phone Number 电话号码的字母组合