Backtracking Lecture 7 🔥 | Combination Sum & Combination Sum II Explained | LeetCode

This is Lecture 7 of my Backtracking Series 🔥

Notes: Telegram Community Group

Telegram Community Channel link: https://t.me/studyplacementcommunity

Telegram Discussion Group link:
https://t.me/+iCezc5Ds9GkwZjdl

Upsolve Leetcode Contest:
   • Leetcode Contests  

Greedy & Heaps:
   • Greedy & Heaps  

Two pointers:
   • Two pointers  

Sliding Window:
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Maths & Geometry:
   • Maths & Geometry  

Stack:
   • Stack  

Set & Map:
   • Set & Map  

Bit manipulation:
   • Bit Manipulation  

Backtracking:
   • Backtracking  

Linked List:
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Binary Search:
   • Binary Search  

Graph:
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Dynamic Progamming:
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In this video, we solve and compare two important backtracking problems:
👉 Combination Sum
👉 Combination Sum II

You will learn:
✔ How repetition is allowed in Combination Sum
✔ Why Combination Sum II does NOT allow reuse
✔ How to skip duplicates correctly
✔ How sorting helps in pruning
✔ Recursion tree for both problems
✔ Complete dry run and code

This lecture helps you understand:
How small constraints change the entire backtracking logic
How to control repetition and duplicates
How pruning reduces time complexity

📌 Watch earlier lectures for fundamentals:
Lecture 1 — Recursion Basics
Lecture 2 — Subsets
Lecture 3 — Lexicographical Subsets
Lecture 4 — Subsets II
Lecture 5 — Combinations
Lecture 6 — Backtracking Patterns

Language: Hindi + English (Hinglish)

🔔 Subscribe for upcoming lectures on Permutations, N-Queens, Sudoku Solver, etc.

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