solves reverse only letters

Author: anishLearnsToCode

README.md

@@ -247,7 +247,7 @@
 | 905 | [Sort Array by Parity](https://leetcode.com/problems/sort-array-by-parity) | |
 | 908 | [Smallest Range I](https://leetcode.com/problems/smallest-range-i) | [![Java](assets/java.png)](src/SmallestRangeI.java) |
 | 914 | [X of a kind in a Deck of Cards](https://leetcode.com/problems/x-of-a-kind-in-a-deck-of-cards) | [![Java](assets/java.png)](src/XOfAKindInADeckOfCards.java) |
-| 917 | [Reverse Only Letters](https://leetcode.com/problems/reverse-only-letters) | |
+| 917 | [Reverse Only Letters](https://leetcode.com/problems/reverse-only-letters) | [![Java](assets/java.png)](src/ReverseOnlyLetters.java) |
 | 922 | [Sort Array by Parity II](https://leetcode.com/problems/sort-array-by-parity-ii) | |
 | 925 | [Long Pressed Name](https://leetcode.com/problems/long-pressed-name) | |
 | 929 | [Unique Email Addresses](https://leetcode.com/problems/unique-email-addresses) | |

src/ReverseOnlyLetters.java

@@ -0,0 +1,16 @@
+public class ReverseOnlyLetters {
+    public static String reverseOnlyLetters(String s) {
+        StringBuilder result = new StringBuilder();
+        int tail = s.length() - 1;
+        while (tail >= 0 && !Character.isAlphabetic(s.charAt(tail))) tail--;
+
+        for (int head = 0 ; head < s.length() ; head++) {
+            if (Character.isAlphabetic(s.charAt(head))) {
+                result.append(s.charAt(tail--));
+                while (tail >=0 && !Character.isAlphabetic(s.charAt(tail))) tail--;
+            } else result.append(s.charAt(head));
+        }
+
+        return result.toString();
+    }
+}