Common algorithm patterns guide

Master common algorithm patterns for coding interviews. Patterns: 1. Two Pointers (sorted arrays, palindromes). 2. Sliding Window (subarray problems, max/min in window). 3. Fast & Slow Pointers (cycle detection in linked lists). 4. Merge Intervals (overlapping ranges). 5. Cyclic Sort (missing numbers in range). 6. In-place Reversal (linked list reversal). 7. BFS/DFS (tree/graph traversal). 8. Binary Search (sorted data, optimization problems). 9. Top K Elements (heaps, quickselect). 10. Dynamic Programming (optimization, counting). For each pattern: recognize problem type, apply template, practice 5-10 problems. Use LeetCode, HackerRank.