Paytm Interview Experience for SDE 2021

I applied on the Paytm career site, I have  2+ Years of Experience Next day, I was contacted by a Talent Acquisition person from Paytm. 

Round 1: Coding Round

Coding Test was taken on Mettl Platform | 60 minutes | 2 coding questions

• I had to implement the alt+tab functionality of the computer keyboard. Using two stacks I solved the problem and 7 out of 10 test cases were successful.
• Count minimum swap to make string palindrome. (https://www.geeksforgeeks.org/count-minimum-swap-to-make-string-palindrome/). I could solve this problem partially. 4 out of 10 test cases passed

Round 2: Technical Interview Round

After 1 week round 2 was scheduled this Round was of 45 minutes, First Interviewer asked me about my current projects for the first 15 minutes, we had a thorough discussion on the same. Then he started with DS Algo questions –

• First Question was to search an element in a rotated sorted array – I told him we will do a linear search then to reduce complexity I gave him the approach to rotate the array to the correct position and then use binary Search but It was taking O(n) complexity again, He tried to give me some hints but I was not able to solve it fully (https://www.geeksforgeeks.org/search-an-element-in-a-sorted-and-pivoted-array/)
• The second question was a hard question from the tree where he asked me Print all nodes at a distance k from a given node. (https://www.geeksforgeeks.org/print-nodes-distance-k-given-node-binary-tree/) , As I was taking some time to understand the question he reduced it to a simple one (https://www.geeksforgeeks.org/print-nodes-at-k-distance-from-root/)  I was able to solve it and write the fully functional code. Then he asked me, do I have any questions – I asked him about technologies they are using in Paytm.

Final Verdict: They decided not to continue with the next rounds with me, as my skillset was not matching with their requirements.