CareerCup

Given two node values for a tree, find LCA. Consider edge cases - (1) If there exists only one value in the tree, return null. (2) If none of the values exist in the tree, return null. (2) Handle ancestors for duplicate values like -
20
/ \
10 50
/ \ / \
10 17 40 60
/ \
5 15

So for above tree if values 5 and 17 are given, there LCA is the upper 10 and not the lower. You can exemplify something I bet :-)

Given a sorted array of size n implemented as ring buffer, so that when array has reached (n-1) index, it will be overwritten from 0th index and likewise it will continue. Given any number, find its index in the array in less than linear time. Interviewer asked to consider the edge cases which I could not quite understand during the interview. I told, the edge cases would be no-element array, array with one element and such.

I will try to state the question. We all know mobile phone's keypad where "2" is mapped to ABC, "3" to DEF and so on. Given any sequence of integers, find all the (matching) combinations in your phone book.

(screening round)
Implement atoi. What would be your approach converting for string to hex.

(screening round)
Given two sorted arrays, merge them into result array with sorting. Time and Space Complexity.