CoolMind

If you cannot measure it, you cannot improve it.

Run-length encoding

Problem Solution Problem This problem was asked by Amazon. Run-length encoding is a fast and simple method of encoding strings. The basic ...

Posted by chunyang on July 28, 2020

Edit distance

Problem Solution Problem This problem was asked by Google. The edit distance between two strings refers to the minimum number of character...

Posted by chunyang on July 28, 2020

Containing water

Problem Solution Problem This problem was asked by Facebook. You are given an array of non-negative integers that represents a two-dimensi...

Posted by chunyang on July 28, 2020

K node from end

Problem Solution Problem This problem was asked by Google. Given a singly linked list and an integer k, remove the kth last element from t...

Posted by chunyang on July 25, 2020

Bracket match

Problem Solution Problem This problem was asked by Facebook. Given a string of round, curly, and square open and closing brackets, return ...

Posted by chunyang on July 25, 2020

Regular expression match

Problem Solution Problem This problem was asked by Facebook. Implement regular expression matching with the following special characters: ...

Posted by chunyang on July 23, 2020

Lock or unlock a binary tree

Problem Solution Problem This problem was asked by Google. Implement locking in a binary tree. A binary tree node can be locked or unlocke...

Posted by chunyang on July 21, 2020

Minimum steps to reach

Problem Solution Problem This problem was asked by Google. You are given an M by N matrix consisting of booleans that represents a board. ...

Posted by chunyang on July 20, 2020