solves #2404: Most Frequent Even Element in java

Author: anishLearnsToCode

Diff for: README.md

@@ -765,7 +765,7 @@
 | 2389 | [Longest Subsequence With Limited Sum](https://leetcode.com/problems/longest-subsequence-with-limited-sum)                                                             |                                                                              [![Java](assets/java.png)](src/LongestSubsequenceWithLimitedSum.java)                                                                               |                                                                                                                                   |
 | 2395 | [Find Subarrays With Equal Sum](https://leetcode.com/problems/find-subarrays-with-equal-sum)                                                                           |                                                                                  [![Java](assets/java.png)](src/FindSubarraysWithEqualSum.java)                                                                                  |                                                                                                                                   |
 | 2399 | [Check Distances Between Same Letters](https://leetcode.com/problems/check-distances-between-same-letters)                                                             |                                                                              [![Java](assets/java.png)](src/CheckDistancesBetweenSameLetters.java)                                                                               |                                                                                                                                   |
-| 2404 | [Most Frequent Even Element](https://leetcode.com/problems/most-frequent-even-element)                                                                                 |                                                                                                                                                                                                                                  |                                                                                                                                   |
+| 2404 | [Most Frequent Even Element](https://leetcode.com/problems/most-frequent-even-element)                                                                                 |                                                                                   [![Java](assets/java.png)](src/MostFrequentEvenElement.java)                                                                                   |                                                                                                                                   |
 | 2409 | [Count Days Spent Together](https://leetcode.com/problems/count-days-spent-together)                                                                                   |                                                                                                                                                                                                                                  |                                                                                                                                   |
 | 2413 | [Smallest Even Multiple](https://leetcode.com/problems/smallest-even-multiple)                                                                                         |                                                                                                                                                                                                                                  |                                                                                                                                   |
 | 2418 | [Sort the People](https://leetcode.com/problems/sort-the-people)                                                                                                       |                                                                                                                                                                                                                                  |                                                                                                                                   |

Diff for: src/MostFrequentEvenElement.java

@@ -0,0 +1,29 @@
+// https://leetcode.com/problems/most-frequent-even-element
+// T: O(N)
+// S: O(N)
+
+import java.util.HashMap;
+import java.util.Map;
+
+public class MostFrequentEvenElement {
+    public int mostFrequentEven(int[] nums) {
+        final Map<Integer, Integer> evenFrequencies = new HashMap<>();
+        int maxFrequency = 0, smallestEvenNumber = -1;
+
+        for (int element : nums) {
+            if (element % 2 == 1) {
+                continue;
+            }
+
+            evenFrequencies.put(element, evenFrequencies.getOrDefault(element, 0) + 1);
+            if (evenFrequencies.get(element) > maxFrequency) {
+                maxFrequency = evenFrequencies.get(element);
+                smallestEvenNumber = element;
+            } else if (evenFrequencies.get(element) == maxFrequency) {
+                smallestEvenNumber = Math.min(smallestEvenNumber, element);
+            }
+        }
+
+        return smallestEvenNumber;
+    }
+}