Associate Software Engineer

Given a singly linked list of integers. Your task is to return the head of the reversed linked list.

For example:

The given linked list is 1 -> 2 -> 3 -> 4-> NULL. Then the reverse linked list is 4 -> 3 -> 2 -> 1 -> NULL and the head of the reversed linked list will be 4.

Follow Up :

Can you solve this problem in O(N) time and O(1) space complexity?

You are given a preorder traversal of a binary search tree. Your task is to find the postorder from the preorder.

Return the root of the BST constructed from the given preorder. The driver code will then use this root to print the post-order traversal.

For example:

You are given preOrder = [10, 5, 1, 7, 40, 50], the binary search tree from the given preorder traversal is 

Hence the answer is [1, 7, 5, 50, 40, 10].

Given a product in limited quantity (example chairs) and there are many customers that want to buy the product with different set of requirements (some customer wanted 5 chairs and some 10 chairs). The customers are coming concurrently. How do you maintain consistency . 
Example:
There are 15 chairs available in inventory
Customer A wanted 7 chairs
Customer B wanted 10 chairs

They are coming concurrently so both will see 15 chairs , but if A books the chair then B cannot and if B books the chair then A cannot.

Design a system that add , delete , update chair .
Add a booking method which also handle the cases of conflict

Why do you want to leave your last company? 

Why do you want to join tekion? 

What does tekion do?

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