1. Given array containing N elements with three distinct numbers, sort them in ascending order. Time complexity has to be O(n). [elements can be anything not necessary, 0|1|2] 
2. Given binary tree, return left leaves sum. [node has to be leaf and left child of parent]
3. Given linked list, reverse last N nodes and return reversed list. Eg 1 - 2 - 3 -4 -5 -6 -7 -8 -9 and K = 3 return 9 - 8 - 7

Design Uber HLD + current project info [ by sde2 or sde3 ]

Design snake and ladder - write actual code not just LLD [hiring manager round]

1. Given binary tree and target value, check if there is path from root to leaf whose sum of nodes  equals target [path sum problem]
2. Given binary tree and target value, check if there is path from any node to leaf such that sum of nodes on that sub path equals target. Path can go up to root but it will not cross root and go into other side of tree [ path can only go up not up and then down][path sum 3 problem]
3. Given grid, start node and destination node, return shortest path from start to destination. You can travel in 4 directions . Diagonal path not allowed [variation of shortest path to find food problem]

Design system to sync status for all reading devices [kindle/read app on iphone]
Design HLD + LLD