Merge pull request #78 from varunu28/master

Created TreeTraversal.java

data_structures/Trees/TreeTraversal.java

@@ -0,0 +1,92 @@
+/**
+ *
+ * @author Varun Upadhyay (https://github.com/varunu28)
+ *
+ */
+
+// Driver Program
+public class TreeTraversal {
+    public static void main(String[] args) {
+        Node tree = new Node(5);
+        tree.insert(3);
+        tree.insert(7);
+
+        // Prints 3 5 7
+        tree.printInOrder();
+        System.out.println();
+
+        // Prints 5 3 7
+        tree.printPreOrder();
+        System.out.println();
+
+        // Prints 3 7 5
+        tree.printPostOrder();
+        System.out.println();
+    }
+}
+
+/**
+ * The Node class which initializes a Node of a tree
+ * Consists of all 3 traversal methods: printInOrder, printPostOrder & printPreOrder
+ * printInOrder: LEFT -> ROOT -> RIGHT
+ * printPreOrder: ROOT -> LEFT -> RIGHT
+ * printPostOrder: LEFT -> RIGHT -> ROOT
+ */
+class Node {
+    Node left, right;
+    int data;
+
+    public Node(int data) {
+        this.data = data;
+    }
+
+    public void insert (int value) {
+        if (value < data) {
+            if (left == null) {
+                left = new Node(value);
+            }
+            else {
+                left.insert(value);
+            }
+        }
+        else {
+            if (right == null) {
+                right = new Node(value);
+            }
+            else {
+                right.insert(value);
+            }
+        }
+    }
+
+    public void printInOrder() {
+        if (left != null) {
+            left.printInOrder();
+        }
+        System.out.print(data + " ");
+        if (right != null) {
+            right.printInOrder();
+        }
+    }
+
+    public void printPreOrder() {
+        System.out.print(data + " ");
+        if (left != null) {
+            left.printPreOrder();
+        }
+        if (right != null) {
+            right.printPreOrder();
+        }
+    }
+
+    public void printPostOrder() {
+        if (left != null) {
+            left.printPostOrder();
+        }
+        if (right != null) {
+            right.printPostOrder();
+        }
+        System.out.print(data + " ");
+    }
+}
+