Unique Morse Code Words Problem & Solution
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:
[".-","-...","-.-.","-..",".","..-.","--.","....","..",".---","-.-",".-..","--","-.","---",".--.","--.-",".-.","...","-","..-","...-",".--","-..-","-.--","--.."]Given an array of strings words where 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 of "-.-.", ".-", and "-...". We will call such a concatenation the transformation of a word.
Return the number of different transformations among all words we have.
See the unique morse code words problem on LeetCode.
C++ Solution
#pragma GCC optimize("Ofast")
#pragma GCC optimization("unroll-loops")
static const int _=[](){std::ios::sync_with_stdio(false);cin.tie(nullptr);cout.tie(nullptr);return 0;}();
class Solution {
public:
int uniqueMorseRepresentations(vector<string>& words) {
vector<string> morse{".-","-...","-.-.","-..",".","..-.","--.","....","..",".---","-.-",".-..","--","-.","---",".--.","--.-",".-.","...","-","..-","...-",".--","-..-","-.--","--.."};
unordered_set<string> unique;
for (int i = 0; i < words.size(); ++i) {
string s;
for (int j = 0; j < words[i].size(); ++j) {
s += morse[words[i][j] - 'a'];
}
unique.insert(s);
}
return unique.size();
}
};