824. Goat Latin*

​​https://leetcode.com/problems/goat-latin/​​

题目描述

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"

Notes:

  • ​​S​​ contains only uppercase, lowercase and spaces. Exactly one space between each word.
  • ​​1 <= S.length <= 150​​.

C++ 实现 1

题目不难, 注意大写.

class Solution {
public:
    string toGoatLatin(string S) {
        stringstream ss(S);
        string word;
        string res;
        unordered_set<char> vowels{'a', 'e', 'i', 'o', 'u', 'A', 'E', 'I', 'O', 'U'};
        int count = 0;
        while (ss >> word) {
            count += 1;
            if (!vowels.count(word[0])) {
                std::reverse(word.begin(), word.end());
                std::reverse(word.begin(), word.end() - 1);
            }
            res += word + "ma" + string(count, 'a') + " ";
        }
        auto space_pos = res.find_last_of(' ');
        res = res.substr(0, space_pos);
        return res;
    }
};