🎓How I Study AIHISA
📖Read
📄Papers📰Blogs🎬Courses
💡Learn
🛤️Paths📚Topics💡Concepts🎴Shorts
🎯Practice
⏱️Coach🧩Problems🧠Thinking🎯Prompts🧠Review
SearchSettings
How I Study AI - Learn AI Papers & Lectures the Easy Way
CustomCC0-1.0#cp0051600

Sequence Periodic Repeats

Thinking Mode

Summary

  • •Phase 5 / string, array, hashing, two pointers
  • •Reasoning-first competitive programming drill

Problem Description

Given an array of length n, find the length of the longest subarray which can be formed by repeating a subarray of length t at least twice (for some t>0). How to read this problem in plain language: - This is a Phase 5 reasoning drill focused on string, array, hashing, two pointers. - Typical lenses to test first: string, array, hash. - Constraints reminder: 1 ≤ n≤2e5; 1 ≤ ai​≤1e9 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; 1 ≤ ai​≤1e9

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.

stringarrayhashperiodicity
stringarrayhashperiodicity