Find the Smallest Missing Positive Integer | HackerRank Software Engineer Prep Kit

Описание: In this video, we solve “Find the Smallest Missing Positive Integer”, a classic and high-frequency problem from HackerRank, commonly asked in Software Engineer interviews.

We explain:
✅ The intuition behind the O(n) solution
✅ Why negative numbers and large values are ignored
✅ How the in-place (O(1) space) algorithm works
✅ Step-by-step dry run with examples
✅ Clean and interview-ready Java code

📌 Who Should Watch This?

🔥 HackerRank Software Engineer Preparation Kit learners

🎓 CS / AI / DS students

💻 Freshers & experienced developers preparing for interviews

🧠 Anyone learning advanced array manipulation

🧩 Problem Highlights

Uses cyclic sort / index placement technique

Avoids extra space

Frequently asked by:

Amazon

Google

Microsoft

Atlassian

BlackRock

🧠 What You’ll Learn

Why the answer always lies between 1 and n+1

How to place numbers at their correct indices

How to avoid infinite loops during swapping

How interviewers expect you to explain this problem

🔥 Why This Video?

This video is part of the Ultimate HackerRank Guide for Software Engineer Interview Preparation, focused on thinking patterns, not memorization.

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