C++实现字符串元音字母反转的两种方法

class Solution {
public:
    string reverseVowels(string s) {
        vector<pair<int, char>> yuan;

        // 设置一个集合装元音字母，然后一个个判断，如果是直接放入yuan，然后再倒序
        set<char> vowels = {'a', 'e', 'i', 'o', 'u', 'A', 'E', 'I', 'O', 'U'};

        for(int i = 0; i < s.size(); i++) {
            if(vowels.find(s[i]) != vowels.end()) {
                yuan.push_back({i, s[i]});
            }
        }
        reverse(yuan.begin(), yuan.end());

        for(int i = 0; i < yuan.size(); i++) {
            s[yuan[i].first] = yuan[yuan.size() - 1 - i].second;
        }

        return s;
    }
};

vector<pair<int, char>> yuan;
yuan.push_back({index, character});
reverse(yuan.begin(), yuan.end());

if(vowels.find(s[i]) != vowels.end())

bool isVowel(char c) {
    return c == 'a' || c == 'e' || c == 'i' || c == 'o' || c == 'u' || 
           c == 'A' || c == 'E' || c == 'I' || c == 'O' || c == 'U';
}

for(int i = 0; i < yuan.size(); i++) {
    s[yuan[i].first] = yuan[yuan.size() - 1 - i].second;
}

class Solution {
public:
    string reverseVowels(string s) {
        int i = 0, j = s.size() - 1;
        
        while (i < j) {
            if (!isVowel(s[i])) {
                i++;
            } else if (!isVowel(s[j])) {
                j--;
            } else {
                swap(s[i], s[j]);
                i++;
                j--;
            }
        }
        return s;
    }
    
    bool isVowel(char c) {
        return c == 'a' || c == 'e' || c == 'i' || c == 'o' || c == 'u' || 
               c == 'A' || c == 'E' || c == 'I' || c == 'O' || c == 'U';
    }
};