Watch tutorials and explanations by expert teachers that walk through solving this problem.
Timothy H Chang
Algorithms Made Easy
CodingVerse
Ghumman Tech
FLAGeek官方频道
Orkhan Gasanov
Trial & ErrCode
ExtremeProgrammer
robzingcod
Solve more problems to master this pattern
![Insert Delete GetRandom O(1) | Day 12 | [June LeetCoding Challenge] [Leetcode #380] [2020]](https://i.ytimg.com/vi/yeTmZxk6-v4/hq720.jpg?sqp=-oaymwEXCNAFEJQDSFryq4qpAwkIARUAAIhCGAE=&rs=AOn4CLApGd-wNkl2FS9nJEAhxeRnQ9oqXA)
