Data Structure tree and graph

Convert the postfix expression,into its correct infix form.
Expression:876-4*/83*+4+5/

• ((8/((7−6)∗4))+(8∗3)+4)/5

• (8/(7−(6∗4))+(8∗3)+4)/5(8 / (7 - (6 4)) + (8 3) + 4) / 5(8/(7−(6∗4))+(8∗3)+4)/5

• (8/((7−6)/4)+8∗(3+4))/5

• ((8/(7−6))∗4+(8∗3)+4)/5

What is the maximum number of nodes at level k in a binary tree?

• 1. 2^k-1

• 1. 2^k

• 1. 2k

• 1. k^2

what will be the output of above code if the binary search tree values are [50 30 40 20 10 70 60 80 90]   low=30 and high=90

• 1. [30,40,50,60,70,80]

• 1. [80,70,60,50,40,30]

• 1. [30,50,70,90]

• 1. [40,60,80]

A social media platform wants to recommend friends to its users based on common interests. The platform represents users as nodes in a graph, and the friendships between users as edges. The recommendation algorithm aims to suggest friends who have a high number of mutual friends.Which algorithm is most suitable for recommending friends based on mutual friends in the graph?

• 1. Breadth-first search (BFS)

• 1. Depth-first search (DFS)

• 1. Dijkstra's algorithm

• Kruskal's algorithm

Given a BST(Binary Search Tree) with values 10,50,150,37,7 and minVal=-9999 maxVal=9999 what is the functionality of the following code

• 2. Checks largest child node in the BST

• 1. Checks the root element is maximum or minimum

• 1. Checks all the BST values are within minVal to maxVal

• 1. Checks the given BST is valid BST or not

Below code finds the Kth smallest number in the binary search tree. But the code contains small logical faults that prevent it from producing the required results. To obtain the output, correct the code

• 3. condition:if (count != k) should be changed to if (count < k)

• 1. condition:if (count != k) should be changed to if (count >=k)  

• 1. condition:if (count != k) should be changed to if (count == k) 

• 1. condition:if (count != k) should be changed to if (count > k)

What happens when the root node is deleted from a BST?

• Tree becomes invalid
  

• Only the left subtree survives

• The entire tree is deleted

• It must be replaced with a node from a subtree

What is the main idea behind a Weight-Balanced Tree?

•  It balances by comparing the heights of sibling subtrees

• It uses hashing to distribute nodes evenly

• It balances based on the total key values in each subtree

• It ensures the tree remains a complete binary tree at all times

Below code is to determine if there exist two distinct nodes in the BST such that their values sum up to a given target ‘k’ 

Why do we decrement the right pointer when sum > k?

• To reduce the sum by moving to a smaller value on the right side

• To increase the sum by moving to a larger value

• To skip duplicate values

• To move towards the middle of the BST for better balance

 The figure shown below is a balanced binary tree. If node 53 is deleted, which of the following nodes will get unbalanced?

• 70

• 55

• 55 and 60

• 60 and 70