Time to give back

Round 1:

• Left view and right view of a tree
• merge 3 sorted arrays and remove duplicates

Round 2:

• Behaviourial questions

Round 3:

• System design for ad recommendations

Round 4:

• Basic calculator (+* only)
• Insert, delete, update, getRandom in O(1)

Waiting for results. was able to code everything and dry run a bunch of examples.