Categories of google inteview questions

Algorithms

Sorting (notes)
Searching (notes)
Graph traversals (notes)
Big-O analysis (notes)

Data structures

Lists (notes)
Stacks and queues (notes)
Trees and graphs (notes on trees; notes on graphs)
Sets (Java interface Set)
Hashmaps (notes)
Heaps (notes)

Coding

Java/C++/Python
Recursion

Basic probability
Power of 2
Div/mod

Operating systems concepts

Threads and processes
Memory management
File sytems and networking