phone ---------- nfa,dfa What is pigeon hole principle? mutex virtual function memory allocation malloc the difference between a struct and a class what is pointer Expand A ^ ( B v C ) java garbage collection What is 4-color theorem ? implementaion of sin and cos in a calculator Difference between ++a and a++? Difference between using # include <stdio.h> and "stdio.h" onsite --------- implement stack using arrays convert nfa to dfa lots and lots of behavioral questions if you had 0's in a linked list of say 5 elements and you want to know which nodes you have already visited, how would you do that? fibonacci using recursion what is one of the problems with recursion? (answer:stack overflow might occur)