Master Algorithm Interviews: Core Topics & Proven Study Plan

These past two years, software engineer interviews have become extremely competitive, with many top graduates failing to secure satisfactory offers due to rising algorithm requirements.

What do algorithm interviews test?

They can be divided into two categories: data structures and algorithm fundamentals and algorithmic thinking .

Data Structures and Algorithm Fundamentals

This part is further split into two points.

(1) Characteristics and basic operations of various data structures

Examples include arrays, queues, stacks, linked lists, trees, and graphs. Stacks and trees are especially important because they appear in many contexts such as DOM trees, virtual DOM, browser execution stacks, and history stacks.

Problems involving stacks and trees are frequent; most tree‑related challenges can be solved with a "stack + DFS" approach.

(2) Complexity analysis

Complexity analysis is the foundation of learning data structures and algorithms. It covers time and space complexity, each with best, worst, and amortized cases, with worst‑case being most commonly used. Analyzing recursive stack space is also crucial.

Algorithmic Thinking (80% of interview points)

After mastering the basics, focus on algorithmic thinking. The five major topics are:

Search (BFS, DFS, backtracking, binary search, etc.)

Brute‑force optimization (two pointers, monotonic stack, prefix sums, etc.)

Dynamic programming

Divide and conquer

Greedy

These topics cover about 80% of interview questions. Less common topics such as bipartite graphs, skip lists, and reservoir sampling are omitted.

How to prepare efficiently

A scientific learning roadmap and solid problem‑solving techniques are the two most important factors. A clear roadmap prevents confusion and loss of confidence; good techniques avoid repeatedly stumbling over the same problems.

The book "Algorithm Mastery" (《算法通关之路》) provides both a complete roadmap and detailed problem‑solving tips, summarizing thousands of LeetCode problems with extensive explanations and illustrations.

Its three strengths are:

Broad coverage of common problem types, all sourced from high‑frequency LeetCode questions.

Problems are linked with a logical difficulty gradient, helping readers understand underlying logic.

Detailed explanations with many diagrams, ideal for beginners.