LeetCode No.17 | StriveZs的博客

LeetCode No.17

LeetCode第十七题

题目描述

给定一个仅包含数字 2-9 的字符串,返回所有它能表示的字母组合。

给出数字到字母的映射如下(与电话按键相同)。注意 1 不对应任何字母。

figure.1

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示例:

输入:"23"
输出:["ad", "ae", "af", "bd", "be", "bf", "cd", "ce", "cf"].

说明:
尽管上面的答案是按字典序排列的,但是你可以任意选择答案输出的顺序。

代码

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import itertools

class Solution(object):
def letterCombinations(self, digits):
"""
:type digits: str
:rtype: List[str]
"""
if digits == "":
return []
# 字典查表
numList = ['2','3','4','5','6','7','8','9']
characterList = [['a','b','c'],['d','e','f'],['g','h','i'],['j','k','l'],['m','n','o'],['p','q','r','s'],['t','u','v'],['w','x','y','z']]
temp = zip(numList,characterList)
dictList = dict(temp)
#print(dictList)

digitsList = list(digits)
numCharaList = []
sumRes = 1
# 统计输入的数字对应的字母
for i in range(len(digitsList)):
numCharaList.append(dictList[digitsList[i]])
#print(numCharaList)

# 生成结果
result = []
temp = list(itertools.product(*numCharaList)) # 调用库来生成列表排列组合
for i in range(len(temp)):
str1 = ''
for j in range(len(list(temp[i]))):
str1 += temp[i][j]
result.append(str1)
return result



if __name__ == '__main__':
s = Solution()
print(s.letterCombinations('23'))
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