Leetcode 130. Surrounded Regions

Given an m x n board of 'X' and 'O', flip all 'O' cells that belong to regions completely surrounded by 'X' to 'X' (regions connected to the border remain unchanged). The core challenge is to identify border-connected 'O' regions (e.g., via DFS/BFS or Union-Find) and flip all other 'O's in-place.

Question Timeline

See when this question was last asked and where, including any notes left by other candidates.

Company

Level

Region

Comments

Your account is free and you can post anonymously if you choose.

Hello Interview Premium

Recent interview questions

System Design Guided Practice

Exclusive content

Learn More

Leetcode 130. Surrounded Regions

Question Timeline

Comments

Questions

Learn

Links

Legal

Contact