Paytm SDE Interview Experience | On Campus 2020

Round 1: Online Assessment, 3 coding questions:

1. Given an Array and a digit k, return the number with maximum occurrence of digit k.
2. Check if a binary tree is subtree of another binary tree
3. Largest Sum Contiguous Subarray

After this, around 50 students were shortlisted for the interviews. All 3 rounds were technical.

Round 1: Questions related to SQL queries, producer consumer problem, deadlock and its solution, semaphores and locks. 2 coding questions were asked:

1. Reverse a string using recursion.
2. Convert Binary tree to Doubly linked list.

Code had to be executed on IDE with screen sharing turned on.

Round 2:

1. Swapped nodes in BST
2. Sliding Window Maximum (Maximum of all subarrays of size k)

Some questions around inheritance and OOPs concepts, as well as discussion on internship projects. Code had to be written on Google Docs.

Round 3: Introduction and discussion on projects followed by 1 coding question. 

1. LRU Cache Implementation
2. Code had to be written on codepad.

Overall they expect you to write fully optimised production level code. Target should be to complete at least 2 questions in 45 mins.

Tips: Do not neglect CS fundamentals.