What to Do When You Can’t Solve DSA Problems: A Step-by-Step Guide

If you’re practicing Data Structures and Algorithms (DSA) problems, you’ve probably hit a roadblock at some point—staring at a problem, feeling stuck, and not knowing how to move forward. That’s completely normal. The key to mastering DSA isn’t speed but understanding. Instead of rushing through problems, take the time to deeply understand the concepts behind them.

Practicing on platforms like LeetCode can be helpful, but if you focus too much on memorizing solutions, you may struggle when faced with a new problem. In this post, we’ll discuss how to approach DSA effectively and truly grasp the concepts.

Why You Shouldn’t Rush Through DSA

1. DSA is Like Building Blocks

Each concept in DSA builds upon previous ones. If you don’t fully understand a topic, the next one will be even harder. For example, if you rush through recursion without mastering it, dynamic programming will feel impossible.

2. Memorizing Solutions Won’t Help

LeetCode and similar platforms are great for practice, but if you only memorize problem patterns, you’ll get stuck when faced with a slightly different question. Instead, focus on understanding why a particular approach works.

3. Understanding Helps in Real Interviews

In coding interviews, companies test problem-solving ability, not memorization. If you rely on memorized solutions, you’ll struggle when interviewers tweak the question. Understanding core principles will help you adapt to different problems.

How to Truly Understand DSA Concepts

1. Break Down Problems Step by Step

Instead of jumping to a solution, break down the problem logically. Ask yourself:

• What is the input?
• What is the expected output?
• What constraints do I need to consider?
• Can I relate this to a problem I’ve solved before?

2. Write Code from Scratch

Don’t just read solutions—write code yourself. Even if you understand an approach, coding it out helps reinforce your learning.

Example: Solving a Two-Sum Problem

Instead of memorizing, understand the logic behind it:

#include <iostream>
#include <unordered_map>
#include <vector>
using namespace std;

vector<int> twoSum(vector<int>& nums, int target) {
    unordered_map<int, int> numMap;
    for (int i = 0; i < nums.size(); i++) {
        int complement = target - nums[i];
        if (numMap.find(complement) != numMap.end()) {
            return {numMap[complement], i};
        }
        numMap[nums[i]] = i;
    }
    return {};
}

int main() {
    vector<int> nums = {2, 7, 11, 15};
    int target = 9;
    vector<int> result = twoSum(nums, target);
    cout << "Indices: " << result[0] << ", " << result[1] << endl;
    return 0;
}

Instead of memorizing this code, understand:

• Why do we use a hash map
• How checking for complement avoids extra loops
• How this improves efficiency over a brute-force approach

3. Revisit the Basics When Stuck

If a concept feels confusing, go back to the basics. For example, if dynamic programming is difficult, revisit recursion and memoization first.

4. Discuss & Explain Concepts

Try explaining a concept to a friend, writing about it, or even speaking out loud. Teaching forces you to simplify and solidify your understanding.

5. Solve Similar Problems

Once you solve a problem, try variations of it. If you solve a binary search problem, try implementing it in different ways, such as recursive and iterative approaches.

Common Mistakes to Avoid

1. Jumping to Solutions Too Quickly – Spend time thinking before looking up solutions.
2. Ignoring Edge Cases – Always test your code with different inputs.
3. Not Analyzing Time Complexity – Understand how your solution scales.
4. Skipping Fundamentals – If you struggle with advanced topics, revisit simpler ones.

Conclusion

Mastering DSA is not about speed but deep understanding. Take your time with each concept, write code yourself, and focus on problem-solving rather than memorization. Over time, you’ll build a strong foundation that will help you tackle any coding challenge confidently.

Ready to Level Up?

• Practice consistently on LeetCode but focus on understanding, not just solving.
• Revisit basic concepts when needed.
• Discuss and explain concepts to strengthen your understanding.

By following these steps, you’ll not only become better at coding but also perform well in technical interviews. Keep going—you’ve got this!