Sliding Window Algorithm Problems. Written by top USACO Finalists, these tutorials will guide you
Written by top USACO Finalists, these tutorials will guide you through your competitive programming journey. Whether you're a seasoned programmer or a curious beginner, understanding this algorithm can significantly enhance your problem-solving toolkit. This guide will delve into the sliding A Bird’s Eye View into Sliding Windows Objective: In this lesson, we'll cover this concept, and focus on these outcomes: You'll learn what the sliding windows algorithm pattern is. Learn how to optimize from O (n²) to O (n) time complexity. Apr 12, 2024 · We'll explore how this technique can be applied to solve problems related to maximum or minimum values in a sliding window, substring search, and more. These are questions that ask you to find a contiguous block of data within a larger dataset. Sliding Window Algorithm – Practice Problems In the sliding window technique, we maintain a window that satisfies the problem constraints. 19 hours ago · Struggling with 'Longest Substring'? The Sliding Window pattern is easy if you follow this step-by-step 'Expand-Contract' framework. Learn the sliding window pattern with step-by-step examples, code templates, and LeetCode practice problems. One of the most common patterns in coding interviews Tagged with python, algorithms, tutorial, beginners. Each solution is optimized, explained with diagrams, and mapped to real-world scenarios like substring processing, analytics, and streaming data. 1 day ago · That immediately rules out the standard sliding-window trick that works for all-positive arrays, because the sum can move in both directions as you expand or shrink a window. Feb 8, 2025 · Master the sliding window algorithm with fixed and variable size solutions. Sliding Window Maximum (Maximum of all subarrays of size K) Jul 14, 2023 · Sliding Window 🚀| Summary with practice questions Sheet (C++) on LeetCode Hi, my name is Amit. I frame the problem like this: every subarray sum can be expressed as a difference of two prefix sums. Perfect for coding interview preparation. Ideal for coding interviews and skill development. How to use Sliding Window Technique with Example?Let's understand the Arrays When to use: fixed-size data, fast access Key patterns: Two pointers Sliding window Prefix sum Kadane’s algorithm (max subarray) Strings Almost same as arrays but watch out for: Frequency Jul 19, 2024 · Sliding Window Algorithm - Variable Length + Fixed Length - DSA Course in Python Lecture 13 Greg Hogg 257K subscribers 986 May 12, 2023 · The Sliding Window technique is a key tool in algorithmic problem-solving that can significantly speed up calculations and improve performance. Dec 10, 2023 · Sliding window problems are a common category of algorithmic challenges encountered during technical interviews. In this article, you will learn how Sliding Window Technique works (with animations), tips and tricks of using it, along with its applications on some sample questions. Nov 26, 2024 · The sliding window technique is a powerful and commonly used approach to solve array and string problems in coding interviews. Return the max sliding window. I have solved more than 1000+ questions on LeetCode and have current ratings of 1950+ (Top 3%) … Mar 17, 2025 · Easy, huh? Let's now examine this approach's algorithm. Sliding Window problems have always confused me, but you are likely to see them in a live coding interview on Data Structures and algorithms, so it's worth learning. The sliding window algorithm solves problems by maintaining a subset of elements that slides over the data, optimizing solutions for problems like subarray sums. The media could not be loaded, either because the server or network failed or because the format is not supported. Sliding Window is more than just fixed or variable length patterns. Example: Longest Subarray with Sum at Most K (Dynamic-Size Window) May 21, 2024 · Sliding Window Algorithm is a technique for reducing the complexity of algorithms. Comprehensive collection of 176+ algorithms for technical interviews - Ananyanagaraj11/coding-toolkit Understand the sliding window technique used in algorithms to solve problems efficiently. Oct 10, 2021 · Sliding windows can be used in a variety of algorithms to solve many types of problems. 💡 Concepts Covered: Variable Sliding Window explained A curated collection of sliding window algorithm problems covering fixed, variable, and conditional windows. Sep 15, 2024 · Hi, my name is Prerna, working at Google as a Software Engineer. Learn key patterns, example problems, and real-world applications in 2025. I have curated and accumulated 25 problems based on sliding window pattern. In this article, we’ll look at the Dec 6, 2025 · In general, sliding windows cut a great deal of repeated handling from substring and subarray scans. Learn how to use the sliding window technique to solve various problems involving strings, arrays, and binary arrays. You need a method that doesn’t rely on monotonic growth. In our case, maintaining a subarray window that satisfies the problem constraints is our sub-problem. Aug 13, 2025 · Auxiliary Space: O (k), Elements stored in the dequeue take O (k) space. Mar 24, 2024 · Sliding Window- Sliding Window Technique is a method used to efficiently solve problems that involve defining a window or range in the input data [list/strings] and then moving that window across Sep 5, 2023 · 10 Sliding Window Leetcode Problems that make you understand it better reference … Feb 15, 2022 · Sliding Window Technique is a popular method in algorithmic problems because of its high efficiency (mostly linear) It helps to avoid computing repetitive problems by computing only the new part that's introduced in the data set and discarding the one that moves out, usually 1 at a time. Can you solve this real interview question? Minimum Window Substring - Given two strings s and t of lengths m and n respectively, return the minimum window substring of s such that every character in t (including duplicates) is included in the window. 3 days ago · The Sliding Window algorithm is a game-changer for problems involving subarrays or substrings. By maintaining only useful elements inside a deque and sliding the window step by step, you can reduce time complexity from brute force to linear time. Moving that window over the entire data will solve our bigger problem. You can only see the k numbers in the window. Jan 10, 2018 · A fellow redditor from /r/cscareerquestions pointed me to this awesome thread on leetcode discuss which reveals the sliding window pattern for solving multiple string (substring) problems. A curated collection of sliding window algorithm problems covering fixed, variable, and conditional windows. This technique shows how a nested for loop in some problems can be converted to a single for loop to reduce the time complexity. This is one of the most important and easiest topics one should cover for Coding Interviews. Nov 20, 2025 · The only sliding window guide you'll ever need. This method is particularly useful when dealing with arrays or strings, offering a way to process data in a linear time complexity. Sliding window technique… Apr 20, 2023 · The Sliding Window algorithm is a powerful technique for reducing the complexity of algorithms. Tagged with slidingwindow, leetcode, algorithms, interviewprep. Here, I cover a basic problem involving the fixed window technique, and another involving the variable A monotonic queue is similar to a monotonic stack, but due to its deque implementation, a monotonic queue has access to both the front and end, making it efficient for sliding window problems. Below is an extension of this problem: Sum of minimum and maximum elements of all subarrays of size k. 4 days ago · Download Citation | Fast Pareto Optimization Using Sliding Window Selection for Problems with Deterministic and Stochastic Constraints | Submodular optimization problems play a key role in This problem is an extension of “Fruit Into Baskets”, and is one of the most asked Sliding Window + HashMap interview questions. It involves defining a window of a specific size that moves across an array or a sequence of elements. The sliding window algorithm is used to reduce the time complexity by converting the nested for loops into a single for loop. It also dies at scale Sep 2, 2025 · Commonly used for problems like finding subarrays with a specific sum, finding the longest substring with unique characters, or solving problems that require a fixed-size window to process elements efficiently. Jun 14, 2023 · Understanding what Sliding Window Algorithm is along with examples, its technique, and implementation in Python, C++, and Java. Can you solve this real interview question? Sliding Window Maximum - You are given an array of integers nums, there is a sliding window of size k which is moving from the very left of the array to the very right. I hope this overview gives you a solid foundation to tackle these Sliding Window Technique is a subset of Dynamic Programming, and it frequently appears in algorithm interviews. Sep 2, 2025 · Commonly used for problems like finding subarrays with a specific sum, finding the longest substring with unique characters, or solving problems that require a fixed-size window to process elements efficiently. Dec 9, 2023 · The Sliding Window Algorithm is among the various other algorithms that are crucial to learning due to its use cases in the range of problems that occur. In this article, you will develop intuitions about Sliding Window pattern. These problems often involve efficiently processing elements sequentially within a This is done by using hashing to quickly look up the presence of an element in the window, and using two pointers to track the start and end of the window. Apr 23, 2024 · The Sliding Window Algorithm is a specific technique used in programming to efficiently solve problems that involves arrays, List, Strings, or other data structures by maintaining a window of Detect Cycle in Linked List 🔁 | Floyd’s Algorithm Explained in 3 Minutes Learn how to detect a cycle in a linked list using the Fast & Slow Pointer technique (Floyd’s Cycle Detection Algorithm) — one of the most important problems for coding interviews. Join us as we unravel the intricacies of the Window Sliding Technique, providing clear explanations, intuitive examples, and step-by-step implementations of various algorithms. The Sliding Window Technique using Deque is a powerful optimization method used to solve problems involving fixed-size subarrays efficiently. leetcode, coding interview question, data structures, data structures and algorithms, faang Oct 30, 2018 · So, basically, sliding window comes in very handy for string problem. This window helps condense two nested loops into a single loop, reducing the time complexity of algorithms. Jul 23, 2025 · The Sliding Window Technique is a powerful algorithmic approach used to solve problems involving arrays or lists where a subarray or subsequence is required to be analyzed. Comprehensive study plan with weekly LeetCode problems covering Two Pointers, Sliding Window, Binary Search, and more. ” It works. 19 hours ago · Stop using nested loops for subarray problems. A frame moves across text or numbers without circling back, which lets Java process long takeuforward is the best place to learn data structures, algorithms, most asked coding interview questions, real interview experiences free of cost. During this process, I came across the Sliding Window technique. In the world of algorithmic problem-solving, efficiency is key. Sep 2, 2025 · Commonly used for problems like finding subarrays with a specific sum, finding the longest substring with unique characters, or solving problems that require a fixed-size window to process elements efficiently. These problems can easily be solved using Brute Force techniques which result in quadratic or exponential time complexity. In this article, we’ll look at the Sep 19, 2023 · The sliding window algorithm pattern is a must-have technique for solving sequential data problems with optimal efficiency. The window is unstable if it violates the problem constraints, and it tries to stabilize by increasing or decreasing its size. Typically we use all of the elements within the window for the problem (for eg - sum of all elements in the window). Also let me know in the comments if you want something to be added. Apr 14, 2025 · The sliding window technique is a game-changer that solves a wide range of coding problems efficiently. This algorithm is used to optimize programs by reducing the need for reusing loops. You will also get a template approach to write code to solve these problems. If there is no such substring, return the empty string "". Today Sep 10, 2023 · This type of sliding window is used when the problem requires adjusting the window size based on specific conditions or constraints. Apr 20, 2021 · 91 Sliding window algorithms can be implemented with a single pointer and a variable for window size. The choice of technique for solving a sliding window problem depends on the specific problem and the constraints of the problem. Window Sliding Algorithm The steps for using the sliding window algorithm are as follows: Compute the sum of the first K elements and store it in the current variable. pat Oct 26, 2020 · Identifying patterns among questions is quite an effective strategy when you are grinding LeetCode in preparation for your upcoming software engineering interviews. Jun 30, 2025 · If you've ever struggled with Sliding Window problems or wondered how they all connect, this post is for you. Sliding Window Algorithm What do you mean by Sliding Window? A window of fixed length can be slide over the input. In the world of coding interviews and algorithmic problem-solving, the sliding window technique stands out as a powerful and efficient approach for tackling a wide range of problems. This method involves maintaining a subset of elements that satisfy The Sliding Window Algorithm is a powerful technique used in computer science to solve various problems efficiently. One powerful technique that often comes to the rescue is the Sliding Window algorithm. Nov 25, 2019 · Problem Solving in Java: Sliding Window Algorithm Earlier this week, I have been practicing programming and attempting to solve problems on LeetCode. Dec 30, 2019 · I recently came across the Sliding Window technique while trying to solve a few algorithmic problems involving arrays or strings. Sliding Window Technique is a subset of Dynamic Programming, and it frequently appears in algorithm interviews. In this video we gonna discuss what Sliding Window problems we will be picking up in this series. As developers, we’re constantly seeking ways to optimize our code and tackle complex problems with elegance. Sliding window technique… Jan 2, 2025 · The Sliding Window Algorithm is used in a very concentrated manner, where the size of the window for calculating any problem or analysing an algorithm is constant throughout the program. It is used such that the need for reusing the loops gets reduced and hence the program gets optimized. By maintaining a dynamic window and utilizing a hash table or array, the algorithm efficiently identifies the longest substring without repeating characters within a given string. 2 days ago · Sliding Window: May allow 4 requests due to its interpolation between windows Fixed Window: Allows 5 requests (the per-second limit), showing poor burst control but higher initial throughput The technique is commonly used in algorithms that involve finding patterns or trends in data, such as finding the maximum/minimum value in a set of data, or counting the number of occurrences of a specific element. . Here I give a subarray problem’s definition: Subarray problems Sep 19, 2023 · The sliding window algorithm pattern is a must-have technique for solving sequential data problems with optimal efficiency. Save it in the variable maximum sum because it is the initial sum, hence the current maximum. The testcases will be generated such that the answer is unique. Jan 11, 2024 · Recently, I was practicing coding problems that focused on Data Structures and Algorithms in preparation for a job change. To reuse the sum from the previous subarray, we will subtract the element going out of the window and add the element now being included in the sliding window. See examples of common interview questions and solutions in C, C++, Java, Python, and other languages. Understand the sliding window technique used in algorithms to solve problems efficiently. This guide will delve into the sliding Apr 20, 2023 · The Sliding Window algorithm is a powerful technique for reducing the complexity of algorithms. A Bird’s Eye View into Sliding Windows Objective: In this lesson, we'll cover this concept, and focus on these outcomes: You'll learn what the sliding windows algorithm pattern is. IntroductionThe world of algorithms is vast and fascinating, filled with countless methods to solve a myriad of problems. Includes practical examples, use cases, and code for real-world problems. A free collection of curated, high-quality competitive programming resources to take you from USACO Bronze to USACO Platinum and beyond. Example 1: Input: s Day 7 — DSA: Why Sliding Window Exists Most beginners solve subarray problems like this: “For every starting index, calculate the sum of the next k elements. Please share this article with someone who is preparing for Jun 6, 2020 · The Sliding Window Algorithm is primarily used for the problems dealing with linear data structures like Arrays, Lists, Strings etc. In May 10, 2023 · Mastering the Art of Problem-Solving: The Sliding Window Algorithm Reflecting on when I first began coding, finding a solution to a problem was a source of immense joy. May 12, 2025 · Master the sliding window technique with this guide featuring Python, Java, and C++ code examples. While it works as a “magic” for subarray problems too. Sliding window can be applied in various problems such as: Finding the maximum/minimum value in a set of data. Templates in 3 languages, 10+ worked examples, debugging checklists, and the exact decision tree FAANG interviewers expect you to know. Each time the sliding window moves right by one position. Jan 27, 2021 · In this post, we will learn what is Sliding Window Algorithm and how to implement it in Java. com with Java. Patreon Link: https://www. I will also walk you through some LeetCode questions to show how to apply the Dec 9, 2023 · The Sliding Window Algorithm is among the various other algorithms that are crucial to learning due to its use cases in the range of problems that occur. May 21, 2024 · Sliding Window Algorithm is a technique for reducing the complexity of algorithms. This will save us from going through the whole subarray to find the sum and, as a result, the algorithm complexity will reduce to O(N). It optimizes your solution to run in linear time and reduces unnecessary complexity in your Can you solve this real interview question? Sliding Window Maximum - You are given an array of integers nums, there is a sliding window of size k which is moving from the very left of the array to the very right. Among these, the sliding window algorithm stands out for its simplicity and efficiency. This article provides an in-depth analysis of using the sliding window algorithm to solve the "Longest Substring Without Repeating Characters" problem. I hope this overview gives you a solid foundation to tackle these Dec 6, 2024 · Learn how to optimize algorithms with the sliding window approach, solve complex problems faster, and reduce time complexity.