Hiring process8 levels
  1. 1 IQ Test
  2. 2 Additional Online Test (If Required)
  3. 3 Office Interview with Hiring Manager
  4. 4 Unpaid Test Task (Motivation Check)
  5. 5 Paid Test Task and Follow-Up Interview
  6. 6 Iterative Paid Test Tasks
  7. 7 Office Verification
  8. 8 Final Interview with the Founder

Problems > The K-th Squarefree Number > Editorial

The K-th Squarefree Number — Solution & Editorial

Back to the Problem

The count of squarefree numbers ≤ x is ∑d μ(d)⌊x/d²⌋, computable in O(√x) with a precomputed Möbius sieve. Binary search for the smallest x whose count reaches K.

Complexity: O(√x log)