Missing Number | DSA for Beginners | Hinglish Explanation скачать в хорошем качестве

Missing Number | DSA for Beginners | Hinglish Explanation

Welcome to NullPointer Academy! 🚀 Yeh hai hamari DSA Playlist ka Nauva (Day 9) video. Aaj hum solve karenge Missing Number problem — ek bahut common aur important array question jo interviews mein frequently aata hai. 🔹 Problem Covered: Missing Number (given array of n distinct numbers from 0..n, find the missing one) 🔹 Language: Hinglish (Easy to Understand) 📌 What you’ll learn in this video: Brute Force Approach Idea: For every number from 0..n check if it exists in the array (nested loops). Step-by-step dry run with example. Time & Space Complexity analysis (O(n²) time, O(1) extra space). Better Approach — Hashmap / HashSet Idea: Insert all elements into an unordered_set and check missing number by scanning 0..n. Dry run, C++ implementation, Time & Space complexity (O(n) time, O(n) space). Optimal Approach 1 — Sum Formula Idea: expected_sum = n*(n+1)/2; missing = expected_sum - actual_sum. Dry run, edge-cases (large n / overflow), code, Complexity (O(n), O(1) space). Optimal Approach 2 — XOR Trick Idea: XOR all indices 0..n with all array elements — paired numbers cancel out, remaining is missing. Dry run, why it works, code, Complexity (O(n), O(1) space). Full C++ implementation — line-by-line explanation (no-nonsense, interview-ready). Edge cases & pitfalls (duplicates, overflow, constraints). Summary & which approach to use when. 👉 Subscribe for Daily Hinglish DSA Videos:    / @nullpointeracademy   💬 Agar aapko video pasand aaye to LIKE 👍, SHARE kare aur SUBSCRIBE kare for regular DSA + Interview Prep content. Koi doubt ho to comment mein poochho — main answer kar dunga!