Question

A sentence S is given, composed of words separated by spaces. Each word consists of lowercase and uppercase letters only.

We would like to convert the sentence to "Goat Latin" (a made-up language similar to Pig Latin.)

The rules of Goat Latin are as follows:

• If a word begins with a vowel (a, e, i, o, or u), append "ma" to the end of the word.
  For example, the word 'apple' becomes 'applema'.
• If a word begins with a consonant (i.e. not a vowel), remove the first letter and append it to the end, then add "ma".
  For example, the word "goat" becomes "oatgma".
• Add one letter 'a' to the end of each word per its word index in the sentence, starting with 1.
  For example, the first word gets "a" added to the end, the second word gets "aa" added to the end and so on.

Return the final sentence representing the conversion from S to Goat Latin.

Example 1:

Input: "I speak Goat Latin" Output: "Imaa peaksmaaa oatGmaaaa atinLmaaaaa"

Example 2:

Input: "The quick brown fox jumped over the lazy dog" Output: "heTmaa uickqmaaa rownbmaaaa oxfmaaaaa umpedjmaaaaaa overmaaaaaaa hetmaaaaaaaa azylmaaaaaaaaa ogdmaaaaaaaaaa"

Analyze

The input are a lots of strings. As a result, we need to convert thesr string to Goat Latin. So, we need to deal with each one string in the input.

• If the first letter is not vowel(aeiouAEIOU), then we need to move the first letter to the last one.
• We need add ma after the string.
• We need add the index number of a for the word in the string at the end of the word.

Solution

class Solution {
public:
    string toGoatLatin(string S) {
      const string vowel = "aeiouAEIOU";
      string res, word;
      istringstream stream(S);
      int index = 0;
        while(stream >> word){
            if( vowel.find(word[0]) == std::string::npos ){
            word = word.substr(1) + word[0];
        }
        index ++;
        res += " "+ word + "ma" + string (index, 'a');
      }
      return res.substr(1);
    }
};