[LeetCode]345. Reverse Vowels of a String解題レポート(C++)

[LeetCode]345. Reverse Vowels of a String解題レポート(C++)
タイトルの説明
Write a function that takes a string as input and reverse only the vowels of a string.
Example 1: Given s = “hello”, return “holle”.
Example 2: Given s = “leetcode”, return “leotcede”.
Note: The vowels does not include the letter “y”.
テーマの大意

文字列内のアクセント文字を

に反転
問題を解く構想.
方法1:

ぐらい探しています.アクセント文字の反転を見つける..

コード実装:

class Solution {
public:
    string reverseVowels(string s) {

        set<char> myset = { 'A','E','I','O','U' };

        int i = 0, j = s.size() - 1;

        while (i < j) {
            char t1 = toupper(s[i]);
            char t2 = toupper(s[j]);
            if (myset.count(t1)&& myset.count(t2)){
                swap(s[i++], s[j--]);
            }
            else if (myset.count(t1)) {
                j--;
            }
            else if (myset.count(t2)) {
                i++;
            }
            else {
                i++; j--;
            }
        }
        return s;

    }
};

//    string  set
class Solution {
public:
    string reverseVowels(string s) {
        int left = 0, right = s.size() - 1;
        string t = "aeiouAEIOU";
        while (left < right) {
            if (t.find(s[left]) == string::npos) ++left;
            else if (t.find(s[right]) == string::npos) --right;
            else swap(s[left++], s[right--]);
        }
        return s;
    }
};

方法2:

用find_first_ofとfind_last_of

コード実装:

class Solution {
public:
    string reverseVowels(string s) {
        int left = 0, right = s.size() - 1;
        while (left < right) {
            left = s.find_first_of("aeiouAEIOU", left);
            right = s.find_last_of("aeiouAEIOU", right);
            if (left < right) {
                swap(s[left++], s[right--]);
            }
        }
        return s;
    }
};