804. Unique Morse Code Words

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, "cab" 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:
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.

804. Unique Morse Code Words
``````struct Solution;

use std::collections::HashSet;

impl Solution {
fn unique_morse_representations(words: Vec<String>) -> i32 {
let map = [
".-", "-...", "-.-.", "-..", ".", "..-.", "--.", "....", "..", ".---", "-.-", ".-..",
"--", "-.", "---", ".--.", "--.-", ".-.", "...", "-", "..-", "...-", ".--", "-..-",
"-.--", "--..",
];
let mut morse: HashSet<String> = HashSet::new();
for w in words {
let mut s: String = "".to_string();
for c in w.chars() {
let m = map[(c as u8 - b'a') as usize];
s += m;
}
morse.insert(s);
}
morse.len() as i32
}
}

#[test]
fn test() {
let words: Vec<String> = vec_string!["gin", "zen", "gig", "msg"];
assert_eq!(Solution::unique_morse_representations(words), 2);
}
``````