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 Cursed Substring > Editorial

The Cursed Substring — Solution & Editorial

Back to the Problem

Digit DP tracking (previous-digit-is-1, already-found-13, tight). It is often easier to count those WITHOUT '13' and subtract, but tracking a 'has13' flag directly works too.

Complexity: O(digits · states)