LeetCode 345. Reverse Vowels of a String 题解
Total Accepted: 20180 Total Submissions: 57018 Difficulty: Easy
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".
public class Solution {
public boolean isVowel(char c) { //这个方法效率远高于 List.contains()方法,去看contains源码
if('A' <= c && c <= 'Z') c += 'a'-'A';
return c=='a' || c=='e' || c=='i' || c=='o' || c=='u';
}
public String reverseVowels(String s) {
char[] charArray = s.toCharArray();
// List<Character> vowels = Arrays.asList('a', 'e', 'i', 'o', 'u', 'A', 'E', 'I', 'O', 'U');
int i = 0, j = charArray.length - 1;
while (i < j){
while( i<j && !isVowel( charArray[i]) ) {
i++;
}
while( i<j && !isVowel( charArray[j]) ) {
j--;
}
char temp = charArray[i];
charArray[i] = charArray[j];
charArray[j] = temp;
i++;
j--;
}
return String.valueOf(charArray);
}
}