Onsite interview round 1:
Similar to this : https://leetcode.com/discuss/interview-question/1693416/google-onsite-recursively-delete-leave-nodes-in-a-multi-tree
Onsite interview round 2:
https://leetcode.com/problems/find-all-possible-recipes-from-given-supplies/
Onsite interview round 3: Googleyness
Onsite interview round 4:
https://leetcode.com/discuss/interview-question/2337984/Google-or-Onsite-or-Song-Shuffler