Amazon Software Development Engineer II interview questions

First they asked for a write up on most challenging project and maximum lines of code written in a project. After my write up get short listed, they called for F2F interview in Hyderabad. First round was a programming round and they asked 3 questions- 1. cross product of m*n matrix. 2. left view of a tree (BFS not accepted). 3. Sorting a link list with numbers greater than zero and last element of linked list is greater than second last element. Second round was a design round. They asked about designing a railway ticketing system. After these two rounds they rejected my candidature.