Lua Coding Practice

Solve 4Sum Problem with Unique Quadruplets using Lua Language

Solve 4Sum Problem with Unique Quadruplets using Lua to enhance your skills with lua coding practice , master coding concepts, and prepare for interviews with practical exercises and detailed solutions.

4Sum Problem with Unique Quadruplets

Difficulty : Hard

Categories :

  • Arrays

Given a sorted array of integers and an integer K, find all unique quadruplets (a, b, c, d) in the array such that a + b + c + d = K. The quadruplets should be returned in sorted order, and each quadruplet should have its elements in non-decreasing order.

Constraints:

  • 4 ≤ arr.length ≤ 200
  • -10⁹ ≤ arr[i] ≤ 10⁹
  • -10⁹ ≤ K ≤ 10⁹
  • Array is sorted in non-decreasing order
  • Solution should run in O(n³) time or better

Examples:

Input: arr = [1,2,3,4,5,6,7], K = 20
Output: [[2,3,7,8],[3,4,6,7]]
Explanation: These are the only quadruplets that sum to 20
Input: arr = [-2,-1,0,1,2], K = 0
Output: [[-2,-1,1,2],[-2,0,0,2],[-1,0,0,1]]
Explanation: These are all quadruplets that sum to 0
Input: arr = [2,2,2,2,2], K = 8
Output: [[2,2,2,2]]
Explanation: The only quadruplet that sums to 8

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Choose from the following categories

Arrays A collection of elements stored in contiguous memory locations, allowing efficient random access and manipulation.

Linked Lists A linear data structure where each element (node) points to the next, offering dynamic memory allocation and efficient insertions/deletions.

Trees A hierarchical data structure with nodes connected by edges, used in applications like databases, file systems, and parsing.

Graphs A collection of nodes (vertices) connected by edges, representing relationships, widely used in networking, routing, and social networks.

Dynamic Programming An optimization technique that solves problems by breaking them into overlapping subproblems and storing their results.

Backtracking A problem-solving method that explores all possibilities recursively, backtracking when a solution is not feasible.

Sorting Algorithms Techniques for arranging elements in a specific order, such as quicksort, mergesort, and bubble sort, essential for data organization.

Searching Algorithms Methods for finding elements in a dataset, such as binary search, linear search, and graph traversal techniques.

Mathematics A field of study involving numbers, calculations, and logical reasoning, forming the foundation for algorithms and problem-solving.

Recursion A programming technique where a function calls itself to solve smaller instances of the same problem, often used in divide-and-conquer approaches.

Bit Manipulation Operations performed directly on binary representations of data, used for efficient computations and optimization tasks.