Sum of alternate leaf nodes in bst in c#

Csharp program for Sum of alternate leaf nodes in bst. Here mentioned other language solution.

``````// Include namespace system
using System;
// Csharp program for
// Sum of alternate leaf nodes in bst
public class TreeNode
{
public int data;
public TreeNode left;
public TreeNode right;
public TreeNode(int data)
{
this.data = data;
this.left = null;
this.right = null;
}
}
public class BinarySearchTree
{
public TreeNode root;
public bool alternate;
public BinarySearchTree()
{
this.root = null;
this.alternate = false;
}
// Insert a new node element
{
// Create a new node
var node = new TreeNode(data);
if (this.root == null)
{
// When add first node in bst
this.root = node;
}
else
{
var find = this.root;
// Add new node to proper position
while (find != null)
{
if (find.data >= data)
{
if (find.left == null)
{
// When left child empty
// So add new node here
find.left = node;
return;
}
else
{
// Otherwise
// Visit to left sub-tree
find = find.left;
}
}
else
{
if (find.right == null)
{
// When right child empty
// So add new node here
find.right = node;
return;
}
else
{
// Visit to right sub-tree
find = find.right;
}
}
}
}
}
public int leafSum(TreeNode node)
{
if (node != null)
{
if (node.left == null && node.right == null)
{
// Case A
// When node is leaf node
// Change status
this.alternate = !this.alternate;
// Check node is alternate or not
if (this.alternate)
{
// When get alternate node
return node.data;
}
}
else
{
// Case B
// When node is internal
// Visit left and right subtree and find alternate node
return this.leafSum(node.left) +
this.leafSum(node.right);
}
}
return 0;
}
public int alternateLeafSum()
{
// Reset alternate leaf node status
this.alternate = false;
return this.leafSum(this.root);
}
public static void Main(String[] args)
{
var tree = new BinarySearchTree();
/*
Binary search tree
-------------------
5
/  \
/    \
/      \
3        19
/ \     /   \
2   4   8     31
/ \    / \
7   15 25  50
*/
// Test
Console.WriteLine(tree.alternateLeafSum());
}
}``````

Output

``34``

Comment

Please share your knowledge to improve code and content standard. Also submit your doubts, and test case. We improve by your feedback. We will try to resolve your query as soon as possible.