CustomCC0-1.0#cpq010-9621810
Permutation Cycle Split
Summary
- •Phase 3 / permutation, cycles, greedy
- •Reasoning-first competitive programming drill
Problem Description
Given a permutation of N numbers 1..N, find the minimal number of contiguous subarrays you must split it into so that each contains a complete cycle in the permutation.
How to read this problem in plain language:
- This is a Phase 3 reasoning drill focused on permutation, cycles, greedy.
- Typical lenses to test first: permutation, cycles, greedy.
- Constraints reminder: 1 <= N <= 2e5
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 <= N <= 2e5
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.
permutationcyclesgreedy