LeetCode 1674: Minimum Moves to Make Array Complementary | Difference Array (Sweep Line)

LeetCode POTD solution explained step-by-step | Java C++ Python. Learn the thinking process from TLE (Time Limit Exceeded) Brute Force to AC (Accepted) Optimal Solution. Why Not To Why... 🔗 Problem Link: ( Code for all languages ) : https://dcodethought.vercel.app/problems/minimum-moves-to-make-array-complementary-1674 Time : 0:00 : Intro 1:24 : Problem understanding and decoding the logic 6:10 : Method 1 Brute Force 21:20 : Method 2 Better 31:00 : Method 3 Difference Array + Prefix Sum 📂 All POTD, Contest Solutions & Many More Explore DCodeThought: https://dcodethought.vercel.app WalkThrough Video : https://youtu.be/MYFQ7XAM4QA 🎯 My Goal With This Channel My aim is not just to show the final solution. My aim is to help you understand why your solution doesn't work and why the correct solution works. On this channel, we don't jump directly from problem → answer. Instead we go through the real thinking process: ❌ From Wrong Answer (WA) / TLE: Trying to check only existing pair sums O(N 2 ), or running a brute force over all possible sums from 2 to 2⋅limit taking O(N⋅L) time. ➡️ To understanding the mistake: Realizing that checking every target for every pair is too slow. We need to update ranges of answers simultaneously! ➡️ To improving the logic: Breaking down the cost for each pair (A,B) into intervals where the cost is 0,1, or 2 moves based on boundaries like A+1, A+B, and B+limit. ✅ Finally reaching Accepted (AC): Using the Difference Array (Sweep Line) Algorithm to record these interval changes in O(1) time, and then calculating the prefix sum to find the global minimum in purely O(N+L) time! You will learn: • How to break down array pairs and analyze cost intervals. • How to convert range addition problems into O(1) updates using a Difference Array. • How to apply Prefix Sums to extract final results from a Sweep Line array. • How to move from brute force → highly optimized interval math. Because in real coding interviews and contests, thinking matters more than memorizing solutions. Here we break down LeetCode POTD, contest problems, and important DSA questions with clear explanations so you can build strong problem-solving skills. If you want to improve your DSA logic, coding intuition, and interview problem solving, this channel is for you. Welcome to DCodeThought — where we focus on thinking, not just coding. 💻 Solutions explained in: Java | C++ | Python 📌 Topics covered: LeetCode POTD Difference Array Technique Sweep Line Algorithm Prefix Sums Array Manipulation & Intervals Data Structures & Algorithms Coding Interview Problems Competitive Programming Logic 🔔 Subscribe for daily problem solving and logical thinking. Tags: LeetCode 1674, 1674 LeetCode, Minimum Moves to Make Array Complementary, Minimum Moves to Make Array Complementary LeetCode, LeetCode 1674 solution, LeetCode 1674 Java, LeetCode 1674 C++, LeetCode 1674 Python, LeetCode POTD, LeetCode Problem of the Day, LeetCode daily challenge, LeetCode POTD today, Difference Array, Sweep Line Algorithm, Prefix Sum, Interval Updates, Range Updates, Array Manipulation, DCodeThought, DSA, Data Structures and Algorithms, DSA in Java, DSA in C++, DSA in Python, competitive programming, competitive programming tutorial, coding interview questions, FAANG interview preparation, software engineering interview, learn coding, DSA preparation, LeetCode Hindi solutions, coding intuition, medium leetcode problems. Hashtags: #LeetCode1674 #MinimumMovesToMakeArrayComplementary #LeetCodePOTD #DSA #DifferenceArray #SweepLine #PrefixSum #Array #Java #CPP #Python #DataStructures #Algorithms #CodingInterview #CompetitiveProgramming #DCodeThought #Programming #Coding #SoftwareEngineering #TechInterview #LearnCoding #CodingLogic #FAANG #100DaysOfCode #CodeNewbie #LeetCodeDailyChallenge