solves most common word

Author: anishLearnsToCode

Diff for: README.md

@@ -1,7 +1,7 @@
 # LeetCode Algorithms
 
-![problems-solved](https://img.shields.io/badge/Problems%20Solved-190/2081-1f425f.svg)
-![problems-solved-java](https://img.shields.io/badge/Java-190/2081-1abc9c.svg)
+![problems-solved](https://img.shields.io/badge/Problems%20Solved-191/2081-1f425f.svg)
+![problems-solved-java](https://img.shields.io/badge/Java-191/2081-1abc9c.svg)
 ![problems-solved-python](https://img.shields.io/badge/Python-186/2081-1abc9c.svg)
 [![PRs Welcome](https://img.shields.io/badge/PRs-welcome-brightgreen.svg)](CONTRIBUTING.md)
 [![cp](https://img.shields.io/badge/also%20see-Competitve%20Programming-1f72ff.svg)](https://github.com/anishLearnsToCode/competitive-programming)
@@ -220,7 +220,7 @@
 | 806 | [Number of Lines to Write String](https://leetcode.com/problems/number-of-lines-to-write-string) | [![Java](assets/java.png)](src/NumberOfLinesToWriteInString.java) |
 | 811 | [Subdomain Visit Count](https://leetcode.com/problems/subdomain-visit-count) | |
 | 812 | [Largest Triangle Area](https://leetcode.com/problems/largest-triangle-area) | [![Java](assets/java.png)](src/LargestTriangleArea.java) |
-| 819 | [Most Common Word](https://leetcode.com/problems/most-common-word) | |
+| 819 | [Most Common Word](https://leetcode.com/problems/most-common-word) | [![Java](assets/java.png)](src/MostCommonWord.java) |
 | 821 | [Shortest Distance to Character](https://leetcode.com/problems/shortest-distance-to-a-character) | |
 | 824 | [Goat Latin](https://leetcode.com/problems/goat-latin) | |
 | 830 | [Positions of Large Groups](https://leetcode.com/problems/positions-of-large-groups) | |

Diff for: src/MostCommonWord.java

@@ -0,0 +1,22 @@
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.Map;
+import java.util.Set;
+
+public class MostCommonWord {
+    public String mostCommonWord(String paragraph, String[] banned) {
+        String text = paragraph.replaceAll("[^a-zA-Z0-9 ]", " ").toLowerCase();
+        Set<String> bannedWords =  new HashSet<>(Arrays.asList(banned));
+        Map<String, Integer> wordFrequencies = new HashMap<>();
+
+        for (String word :  text.split("\\s+")) {
+            if (!bannedWords.contains(word)) {
+                wordFrequencies.put(word, wordFrequencies.getOrDefault(word, 0) + 1);
+            }
+        }
+
+        return Collections.max(wordFrequencies.entrySet(), Map.Entry.comparingByValue()).getKey();
+    }
+}