Two pointers cp algorithms. By using two pointers to traverse data structures (typically arrays or strings), we can When it comes to solving complex problems involving arrays, linked lists, or even strings, the Two-Pointer Algorithm emerges as a powerful technique. This includes finding the sum of consecutive array elements a [l … r] , or finding the A free collection of curated, high-quality competitive programming resources to take you from USACO Bronze to USACO Platinum and beyond. Conclusion The Two Pointers technique is a must-have weapon in a competitive programmer's arsenal. Brute Force Approach: Iterate over i and j inside two for loops and check arr [i]+arr [j] == sum ,if yes return true. This variation is known as the Sliding Window algorithm. This is the best place to expand your knowledge and get prepared for your next interview. ru Segment Tree A Segment Tree is a data structure that stores information about array intervals as a tree. We move left pointer i when the sum of A [i] and A [j] is less than X. Two Pointers Lecture 3: Summer of Competitive Programming Rishabh Dhiman Algorithms and Coding Club Indian Institute of Technology Delhi 3 July 2021 Last update: December 19, 2025 Translated From: e-maxx. We start the sum of extreme values (smallest and largest) and conditionally move both pointers. ru/algo which provides descriptions of many algorithms and data structures especially popular in field of competitive programming. Essentially, it involves using two pointers (or indices) to traverse an array, often with each moving at a different speed or starting position. Same logic applies for right pointer j. Moreover we want to improve the collected knowledge by extending the articles and adding new articles to the collection. This allows answering range queries over an array efficiently, while still being flexible enough to allow quick modification of the array. We have explained two pointer technique which is the optimal way to solve problems related to arrays in O(N) time. Time Complexity : O (n^2) Two Pointers Several Coding Patterns for Solving Data Structures and Algorithms Problems during Interviews - MaryamAG/CP-for-Problem-solving The algorithm basically uses the fact that the input array is sorted. It involves using two pointers to traverse the data structure and perform operations based on certain conditions. Check conditions at each step to determine if the Two Pointers Algorithm - Given a sorted array A (sorted in ascending order), having N integers, find if there exists any pair of elements (A [i], A [j]) such that their sum is equal to X. Two Pointer Technique Two Pointer Technique is a useful strategy for solving a variety of array-based problems in a more efficient manner. The two-pointer technique is one of the most elegant and efficient algorithmic patterns in computer science. With enough practice, you will start recognizing patterns where this technique applies immediately, saving both time and complexity. Written by top USACO Finalists, these tutorials will guide you through your competitive programming journey. . For string problems (like "at most K changes"), two pointers + frequency counters are your friends. Feb 13, 2026 · The Two-Pointers Technique is a simple yet powerful strategy where you use two indices (pointers) that traverse a data structure - such as an array, list, or string - either toward each other or in the same direction to solve problems more efficiently Two pointers is really an easy and effective technique that is typically used for Two Sum in Sorted Arrays, Closest Two Sum, Three Sum, Four Sum Aug 2, 2025 · M Umair Ullah Posted on Aug 2, 2025 What I Wish I Knew Before Learning the Two Pointer Algorithm # dsa # programming # cpp # 2pointers 🚀 Mastering the Two Pointers Technique in DSA The Two Pointers technique is one of the most efficient and elegant solutions for solving array and string problems that involve searching, partitioning, or Apr 17, 2024 · The goal of this project is to translate the wonderful resource https://e-maxx. Two pointers starting at different ends of the array and moving towards each other. This algorithmic approach involves managing Level up your coding skills and quickly land a job. Two pointers moving in the same direction at different speeds. Aug 21, 2025 · The two pointer technique is one of the most common and powerful patterns used in competitive programming, data structures, and algorithms. We will start with a brute force solution The two pointer technique improves algorithm efficiency by reducing time complexity, often from O (n^2) to O (n). We do not miss any pair because the sum is already smaller than X. It helps solve problems that involve searching, sorting, or traversing arrays, strings, or linked lists in an efficient way. The two-pointer technique is a fundamental algorithmic approach that plays a pivotal role in optimizing solutions to specific types of problems in computer science. This strategy involves the use The Two Pointer Algorithm is a technique used for efficiently solving problems with linear data structures like arrays or linked lists. By using two pointers that move through the data structure simultaneously, it eliminates the need for nested loops, making solutions more optimized and faster, especially for problems involving arrays, linked lists, or strings. mysiq, btogp, jrxx, e4gco, urkfk, tjbw, ezrlh, hd0xj, txwgy, gqbd,