原題鏈接在這里：https://leetcode.com/problems/reverse-vowels-of-a-string/

題目：

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".

題解：

典型的two pointers, 到了vowel時對調.

Note: 對調完要再移動雙指針.

若用到Array.asList(arr), arr 這里要用Character型，而不是char型.?

Time Complexity: O(s.length()). Space:O(s.length()), 因為建立了char array.

AC Java:

1 class Solution { 2 Character [] vowels = {'A', 'E', 'I', 'O', 'U', 'a', 'e', 'i', 'o', 'u'}; 3 4 public String reverseVowels(String s) { 5 if(s == null || s.length() == 0){ 6 return s; 7 } 8 9 HashSet<Character> hs = new HashSet<Character>(Arrays.asList(vowels)); 10 11 int i = 0; 12 int j = s.length()-1; 13 char [] sArr = s.toCharArray(); 14 15 while(i<j){ 16 while(i<j && !hs.contains(sArr[i])){ 17 i++; 18 } 19 20 while(i<j && !hs.contains(sArr[j])){ 21 j--; 22 } 23 24 swap(sArr, i, j); 25 i++; 26 j--; 27 } 28 29 return new String(sArr); 30 } 31 32 private void swap(char [] arr, int i, int j){ 33 char temp = arr[i]; 34 arr[i] = arr[j]; 35 arr[j] = temp; 36 } 37 }

?

轉載于:https://www.cnblogs.com/Dylan-Java-NYC/p/5812211.html

總結

以上是生活随笔為你收集整理的LeetCode Reverse Vowels of a String的全部內容，希望文章能夠幫你解決所遇到的問題。

如果覺得生活随笔網站內容還不錯，歡迎將生活随笔推薦給好友。