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 > Departments and Budgets > Editorial

Departments and Budgets — Solution & Editorial

Back to the Problem

Euler tour flattening: a subtree becomes the contiguous interval [tin, tout], so a Fenwick tree over the tour order answers subtree sums with point updates.

Complexity: O((N + Q) log N)