Goat Latin solution and explanation

def to_goat_latin(sentence: str) -> str:
    vowels = 'aeiouAEIOU'
    words = sentence.split()
    goat_latin = []

    for index, word in enumerate(words):
        if word[0] in vowels:
            goat_word = word + 'ma'
        else:
            goat_word = word[1:] + word[0] + 'ma'
        goat_word += 'a' * (index + 1)

        goat_latin.append(goat_word)

    return ' '.join(goat_latin)

# Example usage:
sentence = "I speak Goat Latin"
print(to_goat_latin(sentence))  # Output: "Imaa peaksmaaa oatGmaaaa atinLmaaaaa"

function toGoatLatin(sentence) {
    const vowels = new Set(['a', 'e', 'i', 'o', 'u', 'A', 'E', 'I', 'O', 'U']);
    const words = sentence.split(' ');
    const goatLatinWords = words.map((word, index) => {
        let result = word;
        if (!vowels.has(word[0])) {
            result = word.slice(1) + word[0];
        }
        result += 'ma' + 'a'.repeat(index + 1);
        return result;
    });
    return goatLatinWords.join(' ');
}
// Example usage:
console.log(toGoatLatin("I speak Goat Latin")); // Output: "Imaa peaksmaaa oatGmaaaa atinLmaaaaa"

public class GoatLatin {
    public static String toGoatLatin(String sentence) {
        String[] words = sentence.split(" ");
        StringBuilder result = new StringBuilder();
        String vowels = "aeiouAEIOU";
        for (int i = 0; i < words.length; i++) {
            StringBuilder wordBuilder = new StringBuilder(words[i]);
            if (vowels.indexOf(wordBuilder.charAt(0)) == -1) {
                char firstChar = wordBuilder.charAt(0);
                wordBuilder.deleteCharAt(0);
                wordBuilder.append(firstChar);
            }
            wordBuilder.append("ma");
            for (int j = 0; j <= i; j++) {
                wordBuilder.append('a');
            }
            result.append(wordBuilder).append(" ");
        }
        return result.toString().trim();
    }
    public static void main(String[] args) {
        System.out.println(toGoatLatin("I speak Goat Latin"));  // Output: "Imaa peaksmaaa oatGmaaaa atinLmaaaaa"
    }
}

public class GoatLatin {
    public static string ToGoatLatin(string sentence) {
        var words = sentence.Split(' ');
        var vowelSet = new HashSet<char> {'a', 'e', 'i', 'o', 'u', 'A', 'E', 'I', 'O', 'U'};
        var result = new StringBuilder();

        for (int i = 0; i < words.Length; i++) {
            string word = words[i];
            if (!vowelSet.Contains(word[0])) {
                word = word.Substring(1) + word[0];
            }
            result.Append(word).Append("ma").Append(new string('a', i + 1)).Append(' ');
        }

        return result.ToString().Trim();
    }

    public static void Main() {
        Console.WriteLine(ToGoatLatin("I speak Goat Latin")); // Output: "Imaa peaksmaaa oatGmaaaa atinLmaaaaa"
    }
}

function toGoatLatin(sentence: string): string {
    return sentence
        .split(' ')
        .map((s, i) => {
            let startStr: string;
            if (/[aeiou]/i.test(s[0])) {
                startStr = s;
            } else {
                startStr = s.slice(1) + s[0];
            }
            return `${startStr}ma${'a'.repeat(i + 1)}`;
        })
        .join(' ');
}

use std::collections::HashSet;
impl Solution {
    pub fn to_goat_latin(sentence: String) -> String {
        let set: HashSet<&char> = ['a', 'e', 'i', 'o', 'u'].into_iter().collect();
        sentence
            .split_whitespace()
            .enumerate()
            .map(|(i, s)| {
                let first = char::from(s.as_bytes()[0]);
                let mut res = if set.contains(&first.to_ascii_lowercase()) {
                    s.to_string()
                } else {
                    s[1..].to_string() + &first.to_string()
                };
                res.push_str("ma");
                res.push_str(&"a".repeat(i + 1));
                res
            })
            .into_iter()
            .collect::<Vec<String>>()
            .join(" ")
    }
}