Microsoft Developer interview questions

I submitted my resume at an university technical fair. I got an interview a couple weeks later. The interview was at the career center and it lasted about 45 mins to an hour. Interview was one-on-one. The interview, in general, was pretty relaxed and the interviewer was friendly. Interviewer initially went through my resume and asked specific questions based off it. Afterwards, interviewer asked the more technical questions and asked if I had any questions in general.

Campus recruitment. First there was a written round. MCQs were easy. Programming questions were 1) Print out the last 10 lines of a string. 2)Level wise printing of a binary tree. First Interview: 1)Convert "aaabbcccsss" to "a3b2c3s3" inplace. 2)Find if a linked list is circular Second Interview: 1)Two extra pointers in nodes of a BST, prev and next. Set them to inorder predecessor and successor respectively. Gave a nlogn average solution. Interviewer told me write code which took me nearly 25 minutes. Rejected after this round.