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 > Numbers That Only Climb > Editorial

Numbers That Only Climb — Solution & Editorial

Back to the Problem

Digit DP with prefix subtraction f(R) − f(L−1): the state is the previous digit; the next digit must be ≥ it. Carry a 'tight' flag for the upper bound and a 'leading-zero' flag.

Complexity: O(digits · states)

Watch out: After leading zeros, the first real digit starts a fresh comparison; keeping previous=0 through leading zeros happens to work here since any first digit >= 0.