Merge pull request larissalages#19 from Meuman/master

Added a trie data structure to the data_structures/Java folder

Author: larissalages

data_structures/Java/trie/Trie.java

@@ -0,0 +1,40 @@
+public class Trie{
+    static final int SIZE_OF_ALPHABET = 26;
+    static class TrieNode{
+        TrieNode[] children = new TrieNode[SIZE_OF_ALPHABET];
+        TrieNode(){
+            isEndOfWord = false;
+            for (int i = 0; i < SIZE_OF_ALPHABET; i++){
+                children[i] = null;
+            }
+        }
+    }
+    static TrieNode root;
+
+    static void insert (String key){s
+        int index;
+        int level;
+        TrieNode currentNode = root;
+        for (level = 0; level < key.length(); level++){
+            index = key.charAt(level) - 'a';
+            if (currentNode[index] == null){
+                currentNode[index] = new TrieNode();
+            }
+            currentNode = currentNode.children[index];
+        }
+        currentNode.isEndOfWord = true;
+    }
+
+    static boolean search (String searched_string){
+        TrieNode currentNode = root;
+        for (int level = 0; level < searched_string.length(); level++){
+            int index = searched_string.charAt(level) - 'a';
+            if (currentNode.children[index] != null){
+                currentNode = currentNode.children[index]
+            } else {
+                return false;
+            }
+        }
+        return (currentNode != null && currentNode.isEndOfWord == true)
+    }
+}