Posted on by Kalkicode
Code Binary Search Tree

# Sum of alternate leaf nodes in bst in node js

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

``````// Node JS program for
// Sum of alternate leaf nodes in bst
class TreeNode
{
constructor(data)
{
this.data = data;
this.left = null;
this.right = null;
}
}
class BinarySearchTree
{
constructor()
{
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;
}
}
}
}
}
leafSum(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;
}
alternateLeafSum()
{
// Reset alternate leaf node status
this.alternate = false;
return this.leafSum(this.root);
}
}

function main()
{
var tree = new BinarySearchTree();
/*
Binary search tree
-------------------
5
/  \
/    \
/      \
3        19
/ \     /   \
2   4   8     31
/ \    / \
7   15 25  50
*/
// Test
console.log(tree.alternateLeafSum());
}
// Start program execution
main();``````

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.

Categories
Relative Post