Two Pointers Cheatsheet | Rules You Must Check Before Writing Code скачать в хорошем качестве

Two Pointers Cheatsheet | Rules You Must Check Before Writing Code

This video explains the Two Pointers pattern as a thinking framework. Instead of jumping into code, we focus on the rules you must check before writing a two-pointer solution: Why to use two pointers Same-direction vs opposite-end pointers How pointer initialization affects logic Why every move must reduce the search space This is a cheatsheet-style explanation meant for clarity, not shortcuts. No tricks. No memorization. Best watched before solving two-pointer problems. Topics covered: Two Pointers intent Pointer initialization rules Sorted vs unsorted behavior Movement invariants Common failure reasons 00:00 – Introduction: What this cheatsheet is about 00:17 – Why Two Pointers solutions fail 00:36 – Rule #1: Define your intent before coding 00:54 – Rule #1 (Most Important): Second pointer start (same-direction only) 01:44 – Rule #2: Sorted vs unsorted input (order matters) 02:08 – Rule #3: Pointer movement must reduce search space 02:29 – Final checklist before writing code 03:00 – Classic LeetCode problems → one rule system 03:19 – Why Container With Most Water breaks most solutions 03:46 – Two Pointers: Final takeaway