题目要求

International Morse Code defines a standard encoding where each letter is mapped to a series of dots and dashes, as follows: "a" maps to ".-", "b" maps to "-...", "c" maps to "-.-.", and so on.

Now, given a list of words, each word can be written as a concatenation of the Morse code of each letter. For example, "cba" can be written as "-.-..--...", (which is the concatenation "-.-." + "-..." + ".-"). We'll call such a concatenation, the transformation of a word.

Return the number of different transformations among all words we have.

题目分析及思路

题目给出摩斯码的编码规则，要求返回所有单词不同transformation的个数。找出多少种不同的情况，可以用len(set())的方式进行处理。摩斯码和字母的对应关系可以用字典。

python代码​

class Solution:

def uniqueMorseRepresentations(self, words):

"""

:type words: List[str]

:rtype: int

"""

morse = [".-","-...","-.-.","-..",".","..-.","--.","....","..",".---","-.-",".-..","--","-.","---",".--.","--.-",".-.","...","-","..-","...-",".--","-..-","-.--","--.."]

letter = ['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']

mldict = dict(zip(letter,morse))

res = set()

for word in words:

mword = ""

for w in word:

mword = mword + mldict[w]

res.add(mword)

return len(res)