Algorithm
Problem Name: 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:
[".-","-...","-.-.","-..",".","..-.","--.","....","..",".---","-.-",".-..","--","-.","---",".--.","--.-",".-.","...","-","..-","...-",".--","-..-","-.--","--.."]
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.
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 "--...--.".
Example 2:
Input: words = ["a"] Output: 1
Constraints:
1 <= words.length <= 1001 <= words[i].length <= 12words[i]consists of lowercase English letters.
Code Examples
#1 Code Example with C++ Programming
Code -
C++ Programming
class Solution {
public:
int uniqueMorseRepresentations(vector<string>& words) {
vector<string>table{".-","-...","-.-.","-..",".","..-.","--.","....","..",".---","-.-",".-..","--","-.","---",".--.","--.-",".-.","...","-","..-","...-",".--","-..-","-.--","--.."};
unordered_set < string>s;
for(string x: words){
string t = "";
for(char c: x) t += table[c - 'a'];
s.insert(t);
}
return s.size();
}
};
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Output
#2 Code Example with Java Programming
Code -
Java Programming
class Solution {
private final String[] CODE = {".-","-...","-.-.","-..",".","..-.","--.","....","..",".---","-.-",".-..","--","-.","---",".--.","--.-",".-.","...","-","..-","...-",".--","-..-","-.--","--.."};
public int uniqueMorseRepresentations(String[] words) {
return Arrays.stream(words).map(e -> getEncoding(e)).collect(Collectors.toSet()).size();
}
private String getEncoding(String s) {
StringBuilder sb = new StringBuilder();
for (char c : s.toCharArray()) {
sb.append(CODE[c - 'a']);
}
return sb.toString();
}
}
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Output
#3 Code Example with Python Programming
Code -
Python Programming
class Solution:
def uniqueMorseRepresentations(self, words):
"""
:type words: List[str]
:rtype: int
"""
dic=set()
letters=[".-","-...","-.-.","-..",".","..-.","--.","....","..",".---","-.-",".-..","--","-.","---",".--.","--.-",".-.","...","-","..-","...-",".--","-..-","-.--","--.."]
for word in words:
code=[]
for letter in word: code.append(letters[ord(letter)-ord("a")])
code= "".join(code)
if not code in dic: dic.add(code)
return len(dic)
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Output
#4 Code Example with C# Programming
Code -
C# Programming
using System.Collections.Generic;
using System.Text;
namespace LeetCode
{
public class _0804_UniqueMorseCodeWords
{
private readonly string[] MORSE_CODE = new string[] { ".-", "-...", "-.-.", "-..", ".", "..-.", "--.", "....", "..", ".---", "-.-", ".-..", "--", "-.", "---", ".--.", "--.-", ".-.", "...", "-", "..-", "...-", ".--", "-..-", "-.--", "--.." };
public int UniqueMorseRepresentations(string[] words)
{
var map = new HashSet < string>();
foreach (var word in words)
{
var sb = new StringBuilder();
foreach (var ch in word)
sb.Append(MORSE_CODE[ch - 'a']);
map.Add(sb.ToString());
}
return map.Count;
}
}
}
Input
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