# Open the Lock

> ML preparation item.

- Stable ID: `leetcode-752-open-the-lock`
- Area: Programming
- Topic: Data Structures
- Origin: external
- Expected time: 25 minutes
- Skills: queue, bfs, dictionaries-sets
- Item JSON: https://mlprep.iwase.dev/data/items/leetcode-752-open-the-lock.json

This site does not reproduce the third-party problem.

- Source: LeetCode Problem Set
- Document: LeetCode Problem Set
- Locator: Problem 752: Open the Lock
- Original problem: https://leetcode.com/problems/open-the-lock/
- Official feedback: https://leetcode.com/problems/open-the-lock/
- Answer status: official-interactive-feedback


## Tutoring contract

Ask for the learner's attempt, begin with the smallest useful hint, preserve item ID `leetcode-752-open-the-lock`, and record a real attempt with `recorded_by: "agent"` and `agent_session_id` when available using https://mlprep.iwase.dev/schema/attempt-record.json.