About This Pattern
Master the Backtracking pattern by practicing these problems organized by difficulty.Focus on the Key Signals - these are the indicators that tell you when to use this pattern.
Medium (2)
Subsets
Return all possible subsets of a set of distinct integers.
Key Signals:
Include or exclude each elementBuild incrementallyAll combinations
Letter Combinations of a Phone Number
Return all possible letter combinations that a phone number could represent.
Key Signals:
Map digits to lettersBuild combinationsRecursive exploration