Flipkart Interview Experience | Set 40 (For SDE 1) Improve Improve Like Article Like Save Share Report I was interviewed for Software Development Engineering (SDE1) role Flipkart. Round 1: Machine Coding round: (90 minutes) Given a binary tree as a sequence of (parent, child) tuples: (A B)(A C)(B G)(C H)(E F)(B D)(C E) Write a program to find following errors in the tree: E1: More than 2 children E2: Duplicate Tuples E3: Cycle present E4: Multiple roots E5: Multiple parents Input is a expression containing parent child relations. output is Error codes or success. Sample test cases Input: (A B)(A C)(B G)(C H)(E F)(B D)(C E) Output: Success Input: (A B)(A C)(A D) Output: E1 Input: (A B)(A B) Output: E2 Input: (A B)(B C)(C A) Output: E3 Input: (A B)(C D) Output: E4 Input: (A B)(B C)(A C) Output: E5 Solution Code is written in node.js javascript. Tests are using mocha. Major trick in this question is that the data structure need to hold such data is not a binary tree but a graph. Or a graph with two sets of edges children and parents. I used this DS in javascript to solve: function Node(data) { this.data = data; this.children = []; this.parents = []; } Cycle detection can be done using http://www.geeksforgeeks.org/detect-cycle-in-a-graph/ My solution: https://github.com/niklabh/tree-error-checker Round 2: Face to Face 1. Design a load balancer which implements following methods: add(n) where n is id of instance remove(n) where n is id of instance getRandom() which returns a random instance. All these operation should be of order O(1). Solution: http://stackoverflow.com/questions/5682218/data-structure-insert-remove-contains-get-random-element-all-at-o1 Followup for this question was to change getRandom in such a way that it returns with weighted randomness rather than uniform randomness if weights is associated with instances. Solution:http://stackoverflow.com/questions/4463561/weighted-random-selection-from-array 2. You are given a result of cricket tournament with all the wins and losses. Print the teams in such a way that a winning team is always at the right of losing team. Solution: Store the results as a Directed Acyclic Graph and run topological sort algo. https://www.geeksforgeeks.org/topological-sorting/ Round 3: Face to Face Explain your projects in detail Key metrics about your project i.e. how much load it handled etc. If you are storing same data in separate DBs how will you keeping them in sync. If you are to write your project from scratch what will you change? All Practice Problems for Flipkart ! Last Updated : 31 Jan, 2016 Like Article Save Article Previous Flipkart On-Campus Recruitment Next Barclays Interview Experience | Set 1 (On-Campus Written Test for Software Engg) Share your thoughts in the comments Add Your Comment Please Login to comment...