Round 1:
- Given an array and an operation -> foo(index, value), the value can be either 1 or -1, if foo(index, value) is called, it will add 'value' to all elements from index till end of the array, find minimum number of operation to make all array elements 0.
- Don't remember completely, but it was something like finding a deadlock in a BST.
- Design a scalable meeting room booking system.