文章作者：Tyan 部落格：noahsnail.com  |  CSDN  |  簡書

1. Description

2. Solution

• Version 1

class Solution {
public:
    string reverseVowels(string s) {
        unordered_map<char, char> m;
        m['a'] = 'a';
        m['e'] = 'e';
        m['i'] = 'i';
        m['o'] = 'o';
        m['u'] = 'u';
        m['A'] = 'a';
        m['E'] = 'e';
        m['I'] = 'i';
        m['O'] = 'o';
        m['U'] = 'u';
        int i = 0;
        int j = s.length() - 1;
        while(i < j) {
            if(m.find(s[i]) == m.end()) {
                i++;
            }
            if(m.find(s[j]) == m.end()) {
                j--;
            }
            if(m.find(s[i]) != m.end() && m.find(s[j]) != m.end()) {
                swap(s[i], s[j]);
                i++;
                j--;
            }
        }
        return s;
    }
private:
    void swap(char& a, char& b) {
        char temp = a;
        a = b;
        b = temp;
    }
};
 

• Version 2

class Solution {
public:
    string reverseVowels(string s) {
        unordered_map<char, char> m;
        m['a'] = 'a';
        m['e'] = 'e';
        m['i'] = 'i';
        m['o'] = 'o';
        m['u'] = 'u';
        m['A'] = 'a';
        m['E'] = 'e';
        m['I'] = 'i';
        m['O'] = 'o';
        m['U'] = 'u';
        int i = 0;
        int j = s.length() - 1;
        while(i < j) {
            while(i < j && m.find(s[i]) == m.end()) {
                i++;
            }
            while(i < j && m.find(s[j]) == m.end()) {
                j--;
            }
            swap(s[i++], s[j--]);
        }
        return s;
    }
private:
    void swap(char& a, char& b) {
        char temp = a;
        a = b;
        b = temp;
    }
};
 

Reference