When applying for jobs in North America, data structures and algorithms are at the heart of almost every technical interview, whether it’s for internships or full-time roles. Many companies, especially big tech ones like Google, Meta, and Amazon, usually start their interviews with coding problems on whiteboards or online platforms. These questions don’t just test how many tricks you know, but focus on how you solve problems, how clear your code is, how you handle edge cases, and how well you manage time and space complexity. For international students, language can be a challenge, so it’s important to prepare well and make sure your explanations and code are clear.
Common data structures include arrays, linked lists, stacks, queues, hash tables, heaps, trees, and graphs. Once you have the basics down, it helps to learn common algorithm techniques like two pointers, sliding window, binary search, DFS/BFS, dynamic programming, topological sort, and union-find. From my experience, it’s not about doing as many problems as possible but understanding the connections between different problem types. For example, after mastering “Two Sum,” you should also be able to handle “3Sum,” “4Sum,” and their variations using hash tables and two pointers.
Many international students prepare by practicing problems on LeetCode, often focusing on certain tags like “Array” and “Hash Table” first, then moving on to “Tree,” “Graph,” “DP,” and more. I recommend starting with medium-level, common problems, then trying harder ones. When stuck, don’t rush to check the answer. Try to think from different angles, maybe start with a brute-force solution and improve it step by step. Interviewers usually like to see this kind of gradual improvement.
Besides practicing, it’s helpful to review problems after solving them by writing down your thought process and mistakes. I also practiced with friends, doing mock interviews and discussing problems, which helped me understand better and improved my speaking skills. Overall, data structures and algorithms are a must for technical interviews. Building a solid foundation here is an important and valuable first step for job hunting in North America.
