345. Reverse Vowels of a String

不定期更新leetcode解题java答案。

采用pick one的方式选择题目。 

题意为将给定字符串中的元音字符逆序处理返回。

思路为从前向后、从后向前进行字符检索，若为元音则交换顺序，否则不变。代码如下：

public class Solution {
    public String reverseVowels(String s) {
        char[] chs = new char[s.length()];
        int start = 0, end = s.length() - 1;
        
        while(start <= end){
            char startChar = s.charAt(start), endChar = s.charAt(end);
            if(isVowel(startChar) && isVowel(endChar)){
                chs[start] = endChar;
                chs[end] = startChar;
                start++;
                end--;
            }else{
                if(!isVowel(startChar)){
                    chs[start] = startChar;
                    start++;
                }
                if(!isVowel(endChar)){
                    chs[end] = endChar;
                    end--;
                }
            }
        }
        
        StringBuilder sb = new StringBuilder();
        for(int i = 0; i < s.length(); i++)
            sb.append(chs[i]);
            
        return sb.toString();
    }
    
    public boolean isVowel(char ch){
        return ch == 'a' || ch == 'e' || ch == 'o' || ch == 'i' || ch == 'u'
            || ch == 'A' || ch == 'E' || ch == 'O' || ch == 'I' || ch == 'U';
    }
}