# Triple order traversal of a binary tree in kotlin

Kotlin program for Triple order traversal of a binary tree. Here mentioned other language solution.

``````/*
Kotlin program for
Triple order traversal of a binary tree
*/
// Binary Tree node
class TreeNode
{
var data: Int;
var left: TreeNode ? ;
var right: TreeNode ? ;
constructor(data: Int)
{
// Set node value
this.data = data;
this.left = null;
this.right = null;
}
}
class BinaryTree
{
var root: TreeNode ? ;
constructor()
{
this.root = null;
}
fun tripleOrder(node: TreeNode ? ): Unit
{
if (node != null)
{
// Print preorder node
print(" " + node.data);
// Visit left subtree
this.tripleOrder(node.left);
// Print inorder node
print(" " + node.data);
// Visit right subtree
this.tripleOrder(node.right);
// Print postorder node
print(" " + node.data);
}
}
}
fun main(args: Array < String > ): Unit
{
// Create new binary trees
val tree: BinaryTree = BinaryTree();
/*
4
/ \
/   \
-4     7
/ \     \
2   3     1
/ \   /
6   8 5
/
9
----------------------
Constructing binary tree

*/
tree.root = TreeNode(4);
tree.root?.left = TreeNode(-4);
tree.root?.left?.right = TreeNode(3);
tree.root?.left?.right?.left = TreeNode(6);
tree.root?.left?.right?.left?.left = TreeNode(9);
tree.root?.left?.right?.right = TreeNode(8);
tree.root?.left?.left = TreeNode(2);
tree.root?.right = TreeNode(7);
tree.root?.right?.right = TreeNode(1);
tree.root?.right?.right?.left = TreeNode(5);
// Print triple order
// ----------------------------------
// 4 -4 2 2 2 -4 3 6 9 9 9 6 6 3 8 8 ..
// 8 3 -4 4 7 7 1 5 5 5 1 1 7 4
tree.tripleOrder(tree.root);
}``````

Output

`` 4 -4 2 2 2 -4 3 6 9 9 9 6 6 3 8 8 8 3 -4 4 7 7 1 5 5 5 1 1 7 4``

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