CustomCC0-1.0#ct-p4-012000
Range Add Minimum Index
Summary
- •Phase 4 / segment-tree
- •Reasoning-first competitive programming drill
Problem Description
Support range increment updates and query the leftmost index with minimum value in [l,r].
How to read this problem in plain language:
- This is a Phase 4 reasoning drill focused on segment-tree.
- Typical lenses to test first: segment-tree, lazy-propagation, invariant.
- Constraints reminder: n,q <= 2e5
Mini examples for mental simulation:
1) Boundary example: Update/query where l=r. Explain expected behavior and why naive logic may fail.
2) Adversarial example: Large lazy tags accumulate correctly.
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
- •n,q <= 2e5
Analysis
Key Insight
Operation touches logarithmic nodes with lazy propagation.
segment-treelazy-propagationinvariant