[Leetcode Pattern] Stack / Queue

Stack is used to address LIFO problems while queue for FIFO problems. The concept of data structure is…

[Leetcode] Decode String

Decode parentheses from string → stack. This one is more complicated as variables in and out need computation of just the right sequence.

Description

Given an encoded string, return its decoded string.

[Leetcode] Subarray Product Less Than K

Contiguous elements within array varying self length -> sliding window .

[Leetcode Pattern] Dynamic Programming

A cheet sheet of dp problems in leetcode.

Determinate factors…

[Leetcode] Unique Paths

Matrix problem that leverages dp.

Description

There is a robot on an m x n grid. The robot is initially located at the top-left corner (i.e., grid[0][0]). The robot tries to move to the bottom-right corner (i.e., grid[m - 1][n - 1])…

[Leetcode] Distribute Coins in Binary Tree

A DFS problem that requires special design.

[Leetcode] Flatten Nested List Iterator

Stack / Queue provides similar effect with DFS as it controls the returning sequence of temporary output, but requires less memory space.

Description

[Leetcode] Serialize and Deserialize Binary Tree