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Merge Two Sorted Lists
Merge Two Sorted Lists rewards structured search and good pruning more than raw cleverness. It's a great warm-up that builds structured exploration without a ton of moving parts. If you can explain your pruning, this stops feeling like brute force.
Learn this pattern
Backtracking Pattern
Backtracking explores a decision tree with DFS, choosing an option, recursing, then undoing the choice. Use it for permutations, combinations, subsets, and constraint-satisfaction problems like N-Queens.
Meet your coaches
Talk through the problem while you code. Signed-in reps become prep memory for the next session.
Chat with Fin or Coco right now on mobile.
Start talking through the problem here. Switch to desktop when you're ready to code and run tests.
Start coaching sessionStart a coached rep now. Sign in before or after the session so StrongYes can save what you struggled with to your prep memory.
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Desktop required
Sorry - mobile cannot run the editor and tests yet. Use the next step below or email yourself a link to continue on desktop.
Backtracking Pattern gives you a useful next rep while you are still on your phone.