Introduction

Preparing for a technical interview involving algorithms can be daunting, especially with limited time. However, with focused strategies, it's possible to effectively brush up on key concepts and practice problem-solving skills. This article outlines a structured method to refresh your algorithm knowledge quickly if you have an impending interview.

Prioritize Key Areas

Given the time constraint, it's crucial to focus on algorithm topics most frequently covered in interviews. Below is a list of these key topics, along with brief explanations:

1. Data Structures: Understanding how algorithms interact with different data structures is fundamental. Focus on:
   • Arrays and Strings
   • Linked Lists
   • Trees and Graphs
   • Hash Tables
   • Stacks and Queues
2. Sorting and Searching: Know common algorithms like:
   • Quick Sort, Merge Sort, and Bubble Sort
   • Binary Search
3. Dynamic Programming: Master common problems such as:
   • Fibonacci sequence
   • Knapsack problem
4. Recursion and Backtracking: Practice problems involving:
   • Permutations
   • N-Queens problem
5. Complexity Analysis: Refresh your understanding of:
   • Big O notation
   • Space and time complexities

Study Plan

Here's a recommended study plan over the span of a few days:

Day 1: Foundation

• Morning: Revisit basic data structures. Use resources like visualizations or crash course videos to consolidate your understanding.
• Afternoon: Focus on sorting algorithms. Practice coding them from scratch.
• Evening: Work on Binary Search and variations. Solve problems on platforms like LeetCode or HackerRank.

Day 2: Intermediate

• Morning: Dive into dynamic programming. Start with conceptual problems and gradually move to complex examples.
• Afternoon: Master recursive solutions for common problems. Learn how to trace recursive calls.
• Evening: Engage in mock interviews focusing on these topics.

Day 3: Complexity and Practice

• Morning: Analyze algorithms for time and space efficiency. Compare different approaches to optimizing common solutions.
• Afternoon: Tackle backtracking questions, increase difficulty gradually.
• Evening: Attempt full mock interviews covering mixed topics.

Problem Solving Approach

Understand the Problem:

• Carefully read the problem statement.
• Identify input and output requirements.
• Clarify ambiguity before attempting a solution.

Plan Your Approach:

• Break down the problem into smaller sub-problems.
• Choose the best-fit data structure.
• Sketch your solution with pseudo-code before actual implementation.

Implement and Test:

• Code your solution.
• Test against edge cases and validate using asserts.

Review and Optimize:

• Check for inefficiencies.
• If time permits, attempt a secondary solution or an iterative approach.

Resources for Quick Learning

• Books: "Cracking the Coding Interview" by Gayle Laakmann McDowell
• Web Platforms: LeetCode, HackerRank, CodeSignal
• Video Tutorials: YouTube (channels like Abdul Bari, Computerphile)

Table of Key Points

By organizing your study time effectively and targeting key topics, you can maximize your preparation for a technical interview. Remember to practice solving problems consistently and understand the reasoning behind each solution. This method not only prepares you for coding interviews on short notice but also enhances your general problem-solving skills.