Amazon Software Development Engineer interview questions

Round 1: Ques 1: Rearrange a LinkedList – Before : a->x->b->y->c->z After : a->b->c->z->y->x 1st intuition – Maintain two list for a->b->c and x->y->z respectively. Reverse the second list and join it at the end of the first list. Interviewer : Reversing of LL is not allowed. 2nd intuition – Use of Stack, while traversing the second list which is to be reversed, maintain the elements in a stack and then join them. Interview : Use of stack is not allowed. 3rd intuition – Manipulate the pointers in one-go!!! Ques 2: Find Diameter of a Tree Round 2: Ques 1: Given an array of numbers and a window size, k. Find the max element in each window while traversing the array. Ques 2: k-Reverse a LinkedList Leadership Principle Question Round 3: Design a Library Management System. Extended: Add the concept of Reservations. Provide the minimum time to wait for a Student before he can be issued a Book. e.g 3 Books already issued and new student is 37th in queue for the issue. Leadership Principle Question Round 4: Leadership Principle Question Ques 1: Design a Plugable Cache, i.e. at any time it may be changed from LRU to MFU or LFU, etc. LRU – Least Recently Used MFU – Most Frequently Used Ques 2: Multiple Matrices Input : [[a, b, c] [d, e, f] [x, y, z]] # of Rows and Columns can vary. Output: adx, ady, adz, bdx, …. cfy, cfz Result : Rejected

which project was the most challenging project for you till now? What was challenging about that project? one Coding question which was based on Travelling Salesman problem