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Karunya Muralidharan
Karunya Muralidharan

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🎯 Master Backtracking in Interviews: The 20% Patterns That Solve 90% of Problems

🎯 Master Backtracking in Interviews

Backtracking feels scary at first — but here’s the trick: most interview questions repeat the same patterns. Once you master these, you can adapt them to almost any problem.

💡 Think of them as templates, not solutions.


🔑 Core Backtracking Patterns

  1. Subset Generation (Pick / Not Pick)
  • Base of most problems like subsets, subsequences, power set.
  • Key idea: At each step, choose to include or exclude an element.
  1. Permutation Building (Swap / Mark Visited)
  • Used in string/array permutations, anagrams.
  • Backtracking through all possible orders.
  1. Constraint Satisfaction (Place → Recurse → Remove)
  • Classic for N-Queens, Sudoku.
  • Try a candidate, recurse, undo if invalid.
  1. Path Exploration (DFS with Backtrack)
  • Maze problems, word search, rat in a maze.
  • Move in all directions, backtrack when blocked.
  1. Combination Sum (Target Reduction)
  • Problems like “combination sum” or “coin change.”
  • Choose a number, reduce target, recurse until zero.

🚀 Why This Works

👉 These 5 patterns cover 90%+ of backtracking problems you’ll face in interviews.

👉 Once you spot the pattern, it’s just about adjusting conditions and pruning.


📝 Action Plan for Learners

  • Step 1: Solve 2–3 problems from each pattern.
  • Step 2: Write down the template.
  • Step 3: During interviews, map the problem → to the pattern.

🔥 Next time you see a backtracking problem, don’t panic — ask yourself:

“Which of the 5 patterns is this problem really using?”


✨ PS: I’m building Algopet, a SaaS that helps developers retain DSA patterns through gamified practice and spaced repetition — so you don’t just solve once and forget before the interview.

Already 50+ developers have joined the waitlist — save your spot today for lifetime access when we launch.

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