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 > Digits Alternate Parity > Editorial

Digits Alternate Parity — Solution & Editorial

Back to the Problem

Digit DP with prefix difference f(R) − f(L−1), carrying a tight flag and a leading-zero flag.

Complexity: O(digits · states)

Watch out: Encode 'no previous parity yet' as a distinct state (2) so the first digit is unconstrained.