American Express Global Business Travel Production Support Executive Interview Questions and Answers

Round: Test
Experience: 1. Rotate a matrix by 90 degrees clockwise.( He asked me have you heard of question.I said Yes.Then he asked me to code)2. Find vertical sum of nodes present in same vertical line in binary tree. ( He again asked me have you heard of question. I have heard it but didn’t remember the approach. It took some time and then I started telling my approach.He aasked me to write code and question regarding get sums from left to right , for which I made use of linked hashmap)
Overall It was very cool for me
Total Questions: 2

Round: Test
Experience: 1.Reverse K blocks of nodes in linked list.There are two interviewers this time, probably, guy was senior he was asking me question.He was very particular in coding. Checked every edge case.and asked me evrything.Initially I told the approach and then started coding.2.Find min in stack in O(1)Pretty straightforward written code.Again he checked all edge cases with my code.3. Then asked about counting sort and its code.4. And a simple question on array sorting.

Round: HR Interview
Experience: I thought this was last round as they have said like.She asked me about my strengths and challenges I faced.How I overcame through it1.Basic question on oops concepts.(runtime polymorphism).
2.Design tables for getting all employees under manager. I screwed it little bit.But some how I got answer which I was not satisfied as well.I was expecting result either yes/no.But they called me for another round of interview may be because of my expected salary which was high compared to my previous.

Round: Technical Interview
Experience: 1.Given “aaabbbccc” it should return “a3b3c3″ in place. Initially I explained brute force approach then he said array has 2n space.I was able to remember approach for quicksort and started explaining after which I grew confident on it.He was satisfied.Questions on time complexity of algo and space complexity discussions.2.Again a question on OOPs.This time I was completely wrong in answering it.I thought interview with yatra was closing for me.He was not satisified much with this.Luckily, there was another round with manager.

Round: Other Interview
Experience: 1.He asked me to find words which are having particular pattern.Then I said it was KMP algo. Can I explain it ?? I started explaining approach, may be he was busy with something, he asked me to write pseudo code.He left the room for 15 mins then he came back I had almost completed the code, which he was satisified.Some basic questions on spring ( my previous work was related to it). Then my expected salary and my position If I got selected in yatra were discussed.

College Name: NA