Applied through a headhunter. Phone interview scheduled in 5 days. Two people interviewed me over the phone: a 2:1 interview style over HackerRank. They were patient, but I couldn't understand one of the interviewers' accents (this was what ruined the interview).

What is the difference between stack and heap memory? How does garbage collection work? Static vs. final variable. Difference between C++ and Java.

Programming Question: Write a program to print the level-order of a binary search tree.

             B 
          /       \
      L                O
  /      \          /      \

O M B E /
R G