CustomCC0-1.0#cp005-4001400
Minimal Moves to Palindromic Array
Summary
- •Phase 5 / arrays, greedy, math
- •Reasoning-first competitive programming drill
Problem Description
Given an array of n integers, in one move you can increase or decrease any number by 1. Find the minimal total number of moves to make the array palindromic.
How to read this problem in plain language:
- This is a Phase 5 reasoning drill focused on arrays, greedy, math.
- Typical lenses to test first: arrays, greedy, palindrome.
- Constraints reminder: 1 <= n <= 2*10^5, 1 <= ai <= 10^9
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 <= 2*10^5, 1 <= ai <= 10^9
Analysis
Key Insight
The goal is to force explicit intermediate reasoning before revealing more.
arraysgreedypalindrome