CustomCC0-1.0#p0141700
Tree Diameter After Edge Addition
Summary
- •Phase 1 / tree, diameter, greedy
- •Reasoning-first competitive programming drill
Problem Description
Given a tree with n nodes, you can add one edge between any pair (possibly creating a cycle). What is the minimal possible diameter of the resulting graph?
How to read this problem in plain language:
- This is a Phase 1 reasoning drill focused on tree, diameter, greedy.
- Typical lenses to test first: tree, diameter, graph.
- Constraints reminder: 2 ≤
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
- •2 ≤
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.
treediametergraphgreedy