As Leetcode has not implemented the save button yet, I have decided to collect the most upvoted posts (by some famous authors) with links.
Here is the list please check the posts. I will keep updating the list in the future.
Python Cheat Sheet for Leetcode
https://leetcode.com/discuss/study-guide/2122306/python-cheat-sheet-for-leetcode
The Only Lists You Need For Your Interview Preparation
https://leetcode.com/discuss/interview-question/2069641/the-only-lists-you-need-for-your-interview-preparation
Collections of Important String questions Pattern
https://leetcode.com/discuss/interview-question/2001789/collections-of-important-string-questions-pattern
Dynamic Programming Patterns
https://leetcode.com/discuss/study-guide/458695/dynamic-programming-patterns/990665
C++ Maximum Sliding Window Cheatsheet Template!
https://leetcode.com/problems/frequency-of-the-most-frequent-element/discuss/1175088/C%2B%2B-Maximum-Sliding-Window-Cheatsheet-Template!
Solved all two pointers problems in 100 days.
https://leetcode.com/discuss/study-guide/1688903/Solved-all-two-pointers-problems-in-100-days.
[Python] Powerful Ultimate Binary Search Template. Solved many problems
https://leetcode.com/discuss/general-discussion/786126/python-powerful-ultimate-binary-search-template-solved-many-problems
Top LeetCode posts that you cannot miss
https://leetcode.com/discuss/interview-experience/2016202/top-leetcode-posts-that-you-cannot-miss
A comprehensive guide and template for monotonic stack based problems
https://leetcode.com/discuss/study-guide/2347639/a-comprehensive-guide-and-template-for-monotonic-stack-based-problems