Algorithms

Master the essential algorithms that power efficient solutions. Understanding these techniques is key to solving complex problems under time constraints in technical interviews.

Sorting Algorithms

O(n log n) average

Learn various sorting techniques and their trade-offs.

Key Techniques:

  • Quick Sort
  • Merge Sort
  • Heap Sort
  • Counting Sort
  • Radix Sort

Detailed Guides:

Quick Sort

Searching Algorithms

O(log n) to O(n)

Master efficient search techniques for different scenarios.

Key Techniques:

  • Binary Search
  • Linear Search
  • DFS
  • BFS
  • A* Search

Dynamic Programming

Varies by problem

Solve complex problems by breaking them into subproblems.

Key Techniques:

  • Memoization
  • Tabulation
  • LCS
  • Knapsack
  • DP on Trees

Greedy Algorithms

O(n log n) typical

Make locally optimal choices for global optimization.

Key Techniques:

  • Activity Selection
  • Huffman Coding
  • Interval Scheduling

Backtracking

Exponential

Explore all possible solutions systematically.

Key Techniques:

  • N-Queens
  • Sudoku Solver
  • Permutations
  • Combinations

Divide & Conquer

O(n log n) typical

Break problems into smaller subproblems recursively.

Key Techniques:

  • Merge Sort
  • Quick Sort
  • Binary Search
  • Karatsuba

Graph Algorithms

O(E log V) typical

Solve problems involving graphs and networks.

Key Techniques:

  • Dijkstra
  • Bellman-Ford
  • Floyd-Warshall
  • Kruskal
  • Prim

String Algorithms

O(n + m) typical

Efficient algorithms for string manipulation and matching.

Key Techniques:

  • KMP
  • Rabin-Karp
  • Z-Algorithm
  • Suffix Arrays

Bit Manipulation

O(1) to O(n)

Use bitwise operations for efficient computation.

Key Techniques:

  • AND, OR, XOR
  • Bit Masks
  • Power of 2
  • Count Set Bits

Problem Solving Framework

1. Understand: Read the problem carefully and clarify requirements
2. Plan: Choose the right algorithm and data structure
3. Implement: Write clean, efficient code with proper edge cases
4. Test: Verify with examples and consider time/space complexity
5. Optimize: Look for ways to improve your solution