Subtree check done (comments pending)

Author: rampatra

src/main/java/com/ctci/treesandgraphs/CheckSubtree.java

@@ -6,13 +6,80 @@
  */
 public class CheckSubtree {
 
-    /*private static boolean isT2SubtreeofT1(TreeNode t1, TreeNode t2) {
-            
+    private static boolean isT2SubtreeOfT1(TreeNode t1, TreeNode t2) {
+        if (t1 == null) {
+            return false;
+        } else if (t2 == null) {
+            return true;
+        }
+
+        if (t1.val == t2.val) {
+            if (matchTree(t1, t2)) {
+                return true;
+            }
+        }
+        return isT2SubtreeOfT1(t1.left, t2) || isT2SubtreeOfT1(t1.right, t2);
     }
-    
+
     private static boolean matchTree(TreeNode a, TreeNode b) {
-    }*/
-    
+        if (a == null && b == null) {
+            return true;
+        } else if (a == null) {
+            return false;
+        } else if (b == null) {
+            return true;
+        } else if (a.val != b.val) {
+            return false;
+        } else {
+            return matchTree(a.left, b.left) && matchTree(a.right, b.right);
+        }
+    }
+
     public static void main(String[] args) {
+        /*
+            The BST looks like:
+            
+                      4
+                   /    \
+                  2      8
+                /  \   /  \
+               1   3  6   9
+              /
+             0
+             
+         */
+        TreeNode treeRoot = new TreeNode(4);
+        treeRoot.left = new TreeNode(2);
+        treeRoot.right = new TreeNode(8);
+        treeRoot.left.left = new TreeNode(1);
+        treeRoot.left.right = new TreeNode(3);
+        treeRoot.left.left.left = new TreeNode(0);
+        treeRoot.right.left = new TreeNode(6);
+        treeRoot.right.right = new TreeNode(9);
+        System.out.println(isT2SubtreeOfT1(treeRoot, treeRoot));
+        System.out.println(isT2SubtreeOfT1(treeRoot, treeRoot.left));
+        System.out.println(isT2SubtreeOfT1(treeRoot, treeRoot.right));
+
+        /*
+            The sub-tree:
+            
+                8
+               /
+              6
+         */
+        TreeNode treeRoot2 = new TreeNode(8);
+        treeRoot2.left = new TreeNode(6);
+        System.out.println(isT2SubtreeOfT1(treeRoot, treeRoot2));
+
+        /*
+            The sub-tree:
+            
+                8
+               /
+              9
+         */
+        TreeNode treeRoot3 = new TreeNode(8);
+        treeRoot3.left = new TreeNode(9);
+        System.out.println(isT2SubtreeOfT1(treeRoot, treeRoot3));
     }
-}
+}

src/main/java/com/leetcode/trie/LongestWord.java

@@ -14,7 +14,7 @@ public class LongestWord {
     private class TrieNode {
         char ch;
         HashMap<Character, TrieNode> children = new HashMap<>();
-        String completeWord; // to mark a complete word in the tri data structure
+        String completeWord; // to mark a complete word in the trie data structure
 
         TrieNode(char ch) {
             this.ch = ch;