This LeetCode 34 Solution Broke My Brain 🤯 | Honest Java Walkthrough

Binary search problems look easy… until they’re not 😅

In this video, I walk through **LeetCode Question 34 – Find First and Last Position of Element in Sorted Array**, showing **my real thought process**, including mistakes, edge cases, and why some “clean” textbook solutions don’t always feel intuitive at first.

Instead of jumping straight to the classic double binary search approach, I explored a **two-pointer strategy**, carefully handling duplicates, boundaries, and early exits. This is an **uncut, real-world coding session**, exactly how you’d think during an interview or practice session.

🔍 What you’ll learn:

How to reason about *sorted arrays* beyond textbook binary search
How to handle *duplicates and boundaries safely*
Why early exits can simplify logic
Common mistakes engineers make with indices
Trade-offs between readability and optimal complexity

If you’re preparing for **FAANG interviews**, grinding **LeetCode**, or just want to think like a real engineer, this one’s for you.

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🧠 *Approach Explanation*

Start with two pointers: one from the *start**, one from the **end*
Shrink the search window while checking both sides
As soon as the target is found:

Expand inward to capture *all duplicates*
Return immediately to avoid unnecessary scans
Handle edge cases early:

Empty array
Single element array

This approach trades strict optimality for **clarity and practical reasoning**, which is often valuable in real interviews and debugging scenarios.

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⏱ *Complexity*

*Time Complexity:*
Worst case → *O(n)*
Best case → *O(1)* (early match at boundaries)

*Space Complexity:*
*O(1)* — no extra memory used

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📌 *GitHub:* [https://github.com/NganeEmmanue](https://github.com/NganeEmmanue)
💼 *LinkedIn:* [  / ngane-emmanuel-b25242150  ](  / ngane-emmanuel-b25242150  )
📸 *Instagram:* @nganeemmanuel

I post **real-world LeetCode walkthroughs**, and engineering lessons learned the hard way.