CustomCC0-1.0#P014-1431600
Minimum Cost All-Active Switches
Summary
- •Phase 4 / greedy/flipping/min_cost
- •Reasoning-first competitive programming drill
Problem Description
A line of N bulbs, each can be on (1) or off (0). In one move, you pick an interval [L,R] and flip all bulbs in it. Each flip has a cost equal to the length of the interval. Find the minimal total cost to turn all bulbs on.
How to read this problem in plain language:
- This is a Phase 4 reasoning drill focused on greedy/flipping/mi.
- Typical lenses to test first: greedy, flipping, array.
- Constraints reminder: 1 ≤
Mini examples for mental simulation:
1) Boundary example: Describe why this case is tricky. Explain expected behavior and why naive logic may fail.
2) Adversarial example: Adversarial case where naive greedy/local decision looks correct but fails globally.
Lite-mode writing target:
- Write 1~2 observations that shrink the search space.
- Name one final algorithm and state target complexity explicitly.
- Validate with at least 2 edge cases and one hand simulation.
Constraints
- •1 ≤
Analysis
Key Insight
Use this hint to refine your reasoning. This step should reduce search space or formalize correctness. State why this insight changes your algorithm choice.
greedyflippingarray