CustomCC0-1.0#p0171700
Sum of Minimums on Intervals
Summary
- •Phase 1 / monotonic_stack, range
- •Reasoning-first competitive programming drill
Problem Description
Given an array of n integers, for all intervals (l, r) where 1 ≤ , compute the sum of the minimum of the subarray a[l..r].
How to read this problem in plain language:
- This is a Phase 1 reasoning drill focused on monotoni, range.
- Typical lenses to test first: arrays, range, monotonic stack.
- Constraints reminder: 1 ≤ , 0 ≤
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 ≤ , 0 ≤
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.
arraysrangemonotonic stackenumeration