LeetCode 917. Reverse Only Letters (仅仅反转字母)

 1 class Solution {
 2     public String reverseOnlyLetters(String S) {
 3         char[] charArr = S.toCharArray();
 4         int left = 0;
 5         int right = S.length() - 1;
 6         
 7         while(left < right)
 8         {
 9             if(Character.isLetter(charArr[left]) && Character.isLetter(charArr[right]))
10             {
11                 char temp = charArr[left];
12                 charArr[left] = charArr[right];
13                 charArr[right] = temp;
14                 
15                 left++;
16                 right--;
17             }
18             
19             if(!Character.isLetter(charArr[left]))
20                 left++;
21             if(!Character.isLetter(charArr[right]))
22                 right--;
23 
24         }
25         
26         return new String(charArr);
27     }
28 }