7. Unique Morse Code Words

Posted 2021-11-24 sxuer

Title：

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.

For convenience, the full table for the 26 letters of the English alphabet is given below:

[".-","-...","-.-.","-..",".","..-.","--.","....","..",".---","-.-",".-..","--","-.","---",".--.","--.-",".-.","...","-","..-","...-",".--","-..-","-.--","--.."]

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.

Example 1:

Input: words = ["gin", "zen", "gig", "msg"]
Output: 2
Explanation: 
The transformation of each word is:
"gin" -> "--...-."
"zen" -> "--...-."
"gig" -> "--...--."
"msg" -> "--...--."

There are 2 different transformations, "--...-." and "--...--.".

Note:

• The length of words will be at most 100.
• Each words[i] will have length in range [1, 12].
• words[i] will only consist of lowercase letters.

Analysis of Title：

It meas to connect the words intto the Morse Code, and return the number of defferent transformations.

Test case：

["gin", "zen", "gig", "msg"]

Python：

class Solution(object):
　　def uniqueMorseRepresentations(self, words):
　　"""
　　:type words: List[str]
　　:rtype: int
　　"""
　　if not words:

　　　　return 0
　　wordDic = {
"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":"--.."

　　　　}
　　result = set()
　　for w in words:
　　　　word = ‘‘
　　　　for x in w:
　　　　　　word += wordDic.get(x)
　　　　result.add(word)
　　return len(result)

Analysis of Code：

It give me some words in a list, and I need to return a number about the word.

1. So the first I need to go through the list.

2. And then I also need to get all the letters in words, which go through the words.

3. Get all the letters corresponding to the Morse Code.

4. Put in a set.(set can carry out de-duplication )