solves decrypt string from alphabet to integer mapping

Author: anishLearnsToCode

README.md

@@ -336,7 +336,7 @@
 | 1295 | [Find Numbers With Even Numbers of Digits](https://leetcode.com/problems/find-numbers-with-even-number-of-digits)                                    |              [![Java](assets/java.png)](src/FindNumbersWithEvenNumbersOfDigits.java) [![Python](assets/python.png)](python/find_numbers_with_even_number_of_digits.py)               |                                                                                                                                   |
 | 1299 | [Replace Elements With Greatest Element on Right Side](https://leetcode.com/problems/replace-elements-with-greatest-element-on-right-side)           | [![Java](assets/java.png)](src/ReplaceElementWithGreatestElementOnRightSide.java) [![Python](assets/python.png)](python/replace_element_with_greatest_element_on_right_hand_side.py) |                                                                                                                                   |
 | 1304 | [Find N Unique Integers Sum Up To Zero](https://leetcode.com/problems/find-n-unique-integers-sum-up-to-zero)                                         |                                                         [![Java](assets/java.png)](src/FindNUniqueIntegersSumUpToZero.java)                                                          |                                                                                                                                   |
-| 1309 | [Decrypt String From Alphabet To Integer Mapping](https://leetcode.com/problems/decrypt-string-from-alphabet-to-integer-mapping)                     |                                                                                                                                                                                      |                                                                                                                                   |
+| 1309 | [Decrypt String From Alphabet To Integer Mapping](https://leetcode.com/problems/decrypt-string-from-alphabet-to-integer-mapping)                     |                                                    [![Java](assets/java.png)](src/DecryptStringFromAlphabetToIntegerMapping.java)                                                    |                                                                                                                                   |
 | 1313 | [Decompress Run-Length Encoded Strings](https://leetcode.com/problems/decompress-run-length-encoded-list)                                            |                                                                                                                                                                                      |                                                                                                                                   |
 | 1317 | [Convert Integer to Sum Of Two Non-Zero Integers](https://leetcode.com/problems/convert-integer-to-the-sum-of-two-no-zero-integers)                  |                                                                                                                                                                                      |                                                                                                                                   |
 | 1323 | [Maximum 69 Number](https://leetcode.com/problems/maximum-69-number)                                                                                 |                                                                                                                                                                                      |                                                                                                                                   |

src/DecryptStringFromAlphabetToIntegerMapping.java

@@ -0,0 +1,36 @@
+import java.util.LinkedList;
+import java.util.Queue;
+
+public class DecryptStringFromAlphabetToIntegerMapping {
+    public String freqAlphabets(String s) {
+        final StringBuilder result = new StringBuilder();
+        final Queue<Character> queue = new LinkedList<>();
+        for (int index = 0 ; index  < s.length() ; index++) {
+            if (queue.size() == 2) {
+                if (s.charAt(index) == '#') {
+                    result.append(numberToChar(queue.poll(), queue.poll()));
+                    continue;
+                } else {
+                    result.append(numberToChar(queue.poll()));
+                }
+            }
+            queue.add(s.charAt(index));
+        }
+        while (!queue.isEmpty()) {
+            result.append(numberToChar(queue.poll()));
+        }
+        return result.toString();
+    }
+
+    private char numberToChar(char a, char b) {
+        return numberToChar(10 * (a - '0') + (b - '0'));
+    }
+
+    private char numberToChar(char digit) {
+        return numberToChar(digit - '0');
+    }
+
+    private char numberToChar(int digit) {
+        return (char) (digit + 'a' - 1);
+    }
+}