LeetCodechevron_rightSolve patternschevron_rightmath recursion
schemaReusable solving pattern

math recursion Pattern

Pattern hubs are for building transferable solving frames. Learn the recognition signals first, then drill state definition, update rules, and edge explanation until the pattern feels stable.

database7 problemstune1/4/2 difficulty mixcategory3 linked topics

Pattern brief

Recognize first

Recognizes negative exponent handling is required.

Solve rhythm

State the active state and invariant first, explain how each update preserves them, then pressure-test with counterexamples.

Most common miss

Failing to handle n = INT_MIN correctly when negating.

Recognition signals

  • Recognizes negative exponent handling is required.
  • Uses recursion to optimize repeated multiplications.
  • Look for understanding of recursion and factorials.

Solve flow

  1. 1. Define the active state/window.
  2. 2. Update state while preserving invariants.
  3. 3. Validate with edge-heavy examples.

Common misses

  • Failing to handle n = INT_MIN correctly when negating.
  • Misunderstanding how factorials divide the problem into smaller sections, leading to incorrect permutation generation.
  • Not handling negative numbers or zero correctly, which can lead to incorrect answers.

Recommended Ladder

Problem bank

math recursion pattern bank

Start by scanning with search or difficulty filters, then narrow by linked topics. The bank continues loading inside its own container so the page stays readable.

Continue by topic

Once the pattern itself feels familiar, move back into concrete topic hubs so you can separate the pattern from the changing problem context.

route

Guided Practice Path

AI recommends problems by your level and tracks your progress.

Start Guided Patharrow_forward
Math plus Recursion LeetCode Pattern: 7 Solutions