Amazon Intern interview questions

The written round was relatively easy. It contained 20 multiple choice questions on basic c, algorithms and probability. Some questions from OS and networking were there too but were easy. Coding questions were: 1. Left Rotate alternate k node in a link list. 2. Rotate the given matrix by 90 degrees i.e. the first row becomes the last column and second row becomes the second last column and so on. Interview round 1: Two questions were asked. One puzzle and the other coding question. 1. Given a Binary tree, how will you print it level wise. write efficient code.(further some modification in questions) 2. Find intersection of two link-list. 3.segregate even and odd in a link list. Interview round 2: 1. Given a string, find all permutation and write code to remove duplicate ( use hashing). 2. Given 2d matrix of 0's and 1's in sorted fashion find column with maximum number of 1's. Finally I got internship offer from them