level order btree recurssion

Author: joharbatta

Trees/levelOrderbtree.java

@@ -0,0 +1,65 @@
+
+class Node {
+    int data;
+    Node left;
+    Node right;
+
+    Node(int data) {
+        this.data = data;
+        left = right = null;
+    }
+}
+
+class BinaryTree {
+    Node root;
+
+    BinaryTree() {
+        root = null;
+    }
+
+    BinaryTree(int data) {
+        this.root = new Node(data);
+    }
+
+    int height(Node root) 
+    {
+        if (root == null)
+            return -1;
+        return 1 + Math.max(height(root.left), height(root.right));
+    }
+
+    void printAtLevel(Node root, int level) 
+    {
+        if (root == null)
+            return;
+        if (level == 1) {
+            System.out.print(root.data + " ");
+            return;
+        }
+        printAtLevel(root.left, level - 1);
+        printAtLevel(root.right, level - 1);
+    }
+
+    void levrec(Node root) 
+    {
+        if (root == null)
+            return;
+        int h = height(root);
+        for (int i = 1; i <= h + 1; i++) {
+            printAtLevel(root, i);
+            System.out.println();
+        }
+    }
+}
+
+class levelOrderbtree {
+    public static void main(String[] args) {
+
+        BinaryTree bt = new BinaryTree(2);
+        bt.root.left = new Node(3);
+        bt.root.right = new Node(5);
+        bt.root.left.right = new Node(9);
+        bt.root.right.left = new Node(7);
+        bt.levrec(bt.root);
+    }
+}