Coding interviews

For Two Sum, it's better to find pairs as we go, instead of putting everything into a set and then doing something. This way it's easy to forbid taking the same element twice.
For "delete a node in a linked list", give both pointer to the head and pointer to a node that should be deleted. And a bonus question is solve a problem in O(1) time.

Implement / warm-up
map, set, hashset
Time and memory complexity
Arrays
Strings
Sliding window, two pointers
Recursion
backtracking
DS
stack
queue
linked list
Sorting and searching
In-place
Greedy
DP
Fibonacci, Stairs (1 or 2 steps; 1,2,3 steps; 1-K steps, also in O(N) instead of O(N*K))
min-path in a grid
coin change
knapsack
splitting a sequence into parts
dp on DAG's
Math
Bit manipulation
Hashing, hash table
DS again
trees
TRIE
heap
Graphs
Divide&conquer
Probability, randomization

N-1 distinct numbers from 1 to N, one is missing. Find it.
XOR or rearranging the numbers.
All duplicates but one. Find that single number.
Two missing numbers from 1 to N. Find them.
2-sum, 3-sum.
Get a random number from a stream. Do it in-place.
Simulate rand(1,5) with rand(1, 7). Simulate rand(1, 7) with rand(1, 5).
Simulate a fair coin with a spoiled coin.
How do you swap two numbers without using the third variable?
How do you check if two rectangles overlap with each other?
Huge list: https://www.geeksforgeeks.org/must-do-coding-questions-for-companies-like-amazon-microsoft-adobe/