Paytm Interview Experience ( Backend Developer )
Round 1: First Round was coding round. Two questions were there. (1 hr)
- In given integer array, if any integer is repeating then replace it with a number greater than that number which has not been inserted yet in the array. Eg. 1, 3, 4, 5, 3 Output: 1, 3, 4, 5, 6
- Find a longest common subsequence that all the characters present in the subsequence should be of vowels
Eg : String 1: aieef String 2: klaied Answer: 3 (aie)
Round 2: Second Round was technical round ( 1hr – 1:15hr)
- What is multithreading?
- Sort an array containing 0 and 1 in O(n) time.
- Write a program to find the height of a tree.
- Write a program to reverse the linked list.
- Find an element in array in O(n) comparisons.
Round 3: Third Round was technical round ( 1hr – 1:15hr)
- What are semaphore and mutex?
- What is the internal implementation of HashMap?
- Write a program to find the nth Fibonacci number considering all test cases.
- Write a program to check if the binary tree is height balanced or not.
Round 4: This was Manager Round of Discussion ( 1 hr )
- What is HashMap?
- What should be done if we need the HashMap key to be of any User Defined Type? Eg. An object of any class?
- Implement a class whose object is immutable, like String Class.
- Discussion of my projects.