题目
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.
题目意思
给定一组单词,用莫尔斯码来表示这些单词,因为单词不同有可能莫尔斯码会相同,所以来判断这些单词莫尔斯码有几类?
解题思想
将每个单词的莫尔斯码存入set集合中,因为set中不能有重复,所以最后set的长度就是结果。
C++代码
class Solution {
public:
int uniqueMorseRepresentations(vector<string>& words) {
//将26个字母的摩尔斯码存入m
vector<string> m = {".-","-...","-.-.","-..",".","..-.","--.","....","..",".---","-.-",".-..","--","-.","---",".--.","--.-",".-.","...","-","..-","...-",".--","-..-","-.--","--.."};
string s;
//将单词的莫尔斯码存入set中
set<string> result;
for( auto tmp:words){
for( auto c:tmp ) s += m[c-'a'];
result.insert( s );
s.clear();
}
return result.size();
}
};