Top 50 combinatorics Interview Questions
The most frequently asked combinatorics questions across all roles and companies, ranked by real interview frequency. Updated daily.
Count stair-climbing routes using dynamic programming for one-step and two-step moves.
Cisco Restaurant + Bar
Adobe
CiscoGenerate the power set of distinct elements using backtracking, including the empty subset.
Scribd
Current (NY)
ChewyUse sorted backtracking to find every unique combination of input integers that reaches a target without reusing elements.
Instacart
Hewlett Packard Enterprise | HPEGenerate every N-Queens board using backtracking with column and diagonal sets for constant-time conflict checks.
DoverAArzooo
CitadelGenerate every well-formed parentheses combination using backtracking and pruning.
UKGSign up to see every question
Create a free account to unlock this list and practice real interview questions.
Calculate unique pairwise handshakes across multiple conference phases using combinatorial counting.
Capgemini FSSBU
Capgemini Government SolutionsGenerate the nth Pascal triangle row using binomial coefficients with O(n) time and O(n) output space.
HandshakeGenerate every unique permutation of a string using frequency-count backtracking.
Persistent Systems
Persistent