solves #2325: Decode the Message in java

Author: anishLearnsToCode

README.md

@@ -747,15 +747,15 @@
 | 2315 | [Count Asterisks](https://leetcode.com/problems/count-asterisks)                                                                                                       |                                              [![Java](assets/java.png)](src/CountAsterisks.java) [![Python](assets/python.png)](python/successfull_pairs_of_spells_and_potions.py)                                               |                                                                                                                                   |
 | 2316 | [Count Unreachable Pairs of Nodes in an Undirected Graph](https://leetcode.com/problems/count-unreachable-pairs-of-nodes-in-an-undirected-graph)                       |                                                                [![Python](assets/python.png)](python/count_unreachable_pair_of_node_in_an_undirectable_graph.py)                                                                 |                                                                                                                                   |
 | 2319 | [Check if Matrix Is X-Matrix](https://leetcode.com/problems/check-if-matrix-is-x-matrix)                                                                               |                                                                                       [![Java](assets/java.png)](src/CountAsterisks.java)                                                                                        |                                                                                                                                   |
-| 2325 | [Decode the Message](https://leetcode.com/problems/decode-the-message)                                                                                                 |                                                                [![Python](assets/python.png)](python/count_unreachable_pair_of_node_in_an_undirectable_graph.py)                                                                 |                                                                                                                                   |
-| 2331 | [Evaluate Boolean Binary Tree](https://leetcode.com/problems/evaluate-boolean-binary-tree)                                                                             |                                                                [![Python](assets/python.png)](python/count_unreachable_pair_of_node_in_an_undirectable_graph.py)                                                                 |                                                                                                                                   |
-| 2335 | [Minimum Amount of Time to Fill Cups](https://leetcode.com/problems/minimum-amount-of-time-to-fill-cups)                                                               |                                                                [![Python](assets/python.png)](python/count_unreachable_pair_of_node_in_an_undirectable_graph.py)                                                                 |                                                                                                                                   |
+| 2325 | [Decode the Message](https://leetcode.com/problems/decode-the-message)                                                                                                 |                                                                                      [![Java](assets/java.png)](src/DecodeTheMessage.java)                                                                                       |                                                                                                                                   |
+| 2331 | [Evaluate Boolean Binary Tree](https://leetcode.com/problems/evaluate-boolean-binary-tree)                                                                             |                                                                                                                                                                                                                                  |                                                                                                                                   |
+| 2335 | [Minimum Amount of Time to Fill Cups](https://leetcode.com/problems/minimum-amount-of-time-to-fill-cups)                                                               |                                                                                                                                                                                                                                  |                                                                                                                                   |
 | 2439 | [Minimize Maximum of Array](https://leetcode.com/problems/minimize-maximum-of-array)                                                                                   |                                                                               [![Python](assets/python.png)](python/minimize_maximum_of_array.py)                                                                                |                                                                                                                                   |
-| 2341 | [Maximum Number of Pairs in Array](https://leetcode.com/problems/maximum-number-of-pairs-in-array)                                                                     |                                                                [![Python](assets/python.png)](python/count_unreachable_pair_of_node_in_an_undirectable_graph.py)                                                                 |                                                                                                                                   |
-| 2347 | [Best Poker Hand](https://leetcode.com/problems/best-poker-hand)                                                                                                       |                                                                [![Python](assets/python.png)](python/count_unreachable_pair_of_node_in_an_undirectable_graph.py)                                                                 |                                                                                                                                   |
+| 2341 | [Maximum Number of Pairs in Array](https://leetcode.com/problems/maximum-number-of-pairs-in-array)                                                                     |                                                                                                                                                                                                                                  |                                                                                                                                   |
+| 2347 | [Best Poker Hand](https://leetcode.com/problems/best-poker-hand)                                                                                                       |                                                                                                                                                                                                                                  |                                                                                                                                   |
 | 2348 | [Number of Zero-Filled Subarrays](https://leetcode.com/problems/number-of-zero-filled-subarrays)                                                                       |                                                                            [![Python](assets/python.png)](python/number_of_zero_filled_subarrays.py)                                                                             |                                                                                                                                   |
-| 2351 | [First Letter to Appear Twice](https://leetcode.com/problems/first-letter-to-appear-twice)                                                                             |                                                                [![Python](assets/python.png)](python/count_unreachable_pair_of_node_in_an_undirectable_graph.py)                                                                 |                                                                                                                                   |
-| 2357 | [Make Array Zero by Subtracting Equal Amounts](https://leetcode.com/problems/make-array-zero-by-subtracting-equal-amounts)                                             |                                                                [![Python](assets/python.png)](python/count_unreachable_pair_of_node_in_an_undirectable_graph.py)                                                                 |                                                                                                                                   |
+| 2351 | [First Letter to Appear Twice](https://leetcode.com/problems/first-letter-to-appear-twice)                                                                             |                                                                                                                                                                                                                                  |                                                                                                                                   |
+| 2357 | [Make Array Zero by Subtracting Equal Amounts](https://leetcode.com/problems/make-array-zero-by-subtracting-equal-amounts)                                             |                                                                                                                                                                                                                                  |                                                                                                                                   |
 | 2360 | [Longest Cycle in a Graph](https://leetcode.com/problems/longest-cycle-in-a-graph)                                                                                     |                                                                                 [![Python](assets/python.png)](python/longest_cycle_in_graph.py)                                                                                 |                                                                                                                                   |
 | 2363 | [Merge Similar Items](https://leetcode.com/problems/merge-similar-items)                                                                                               |                                                                                                                                                                                                                                  |                                                                                                                                   |
 | 2367 | [Number of Arithmetic Triplets](https://leetcode.com/problems/number-of-arithmetic-triplets)                                                                           |                                                                                                                                                                                                                                  |                                                                                                                                   |

src/DecodeTheMessage.java

@@ -0,0 +1,35 @@
+// https://leetcode.com/problems/decode-the-message
+// T: O(|key| + |message|)
+// S: O(1)
+
+import java.util.HashMap;
+import java.util.Map;
+
+public class DecodeTheMessage {
+    public String decodeMessage(String key, String message) {
+        final Map<Character, Character> mapping = getSubstitutionMap(key);
+        final StringBuilder result = new StringBuilder();
+        System.out.println(mapping);
+
+        for (int index = 0 ; index < message.length() ; index++) {
+            if (message.charAt(index) == ' ') {
+                result.append(' ');
+            } else {
+                result.append(mapping.get(message.charAt(index)));
+            }
+        }
+
+        return result.toString();
+    }
+
+    private Map<Character, Character> getSubstitutionMap(String key) {
+        final Map<Character, Character> result = new HashMap<>();
+        char letter = 'a';
+        for (int index = 0 ; index < key.length() ; index++) {
+            if (!result.containsKey(key.charAt(index)) && key.charAt(index) != ' ') {
+                result.put(key.charAt(index), letter++);
+            }
+        }
+        return result;
+    }
+}