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Combinatorics
Backend Developer
Combinatorics questions
9 questions on Combinatorics for backend developers, easiest first.
Easy
3
How many subarrays exist
easy
Number of subsets of four items
easy
Orderings of four distinct items
easy
Medium
4
Distinct BSTs with keys 1, 2, 3
medium
Ways to pick 3 of 10
medium
Arrangements of the word BANANA
medium
Binary search trees from 3 keys
medium
Hard
2
Sum of all subarray sums
hard
Balanced strings of three bracket pairs
hard
