Given an array nums of n integers, return an array of all the unique quadruplets [nums[a], nums[b], nums[c], nums[d]] such that: a, b, c, and d are distinct. You may return the answer in any order. …

Aug 13, 2025 · We have discussed how to find if a quadruple with given sum exists or not in an array. We are going to extend the ideas here to find all distinct Quadruplets. We run 4 nested loops to …

In-depth solution and explanation for LeetCode 18. 4Sum in Python, Java, C++ and more. Intuitions, example walk through, and complexity analysis. Better than official and forum solutions.

The two-pointer technique from 2Sum and 3Sum extends naturally to 4Sum. After sorting, we fix the first two elements with nested loops, then use two pointers to find pairs that complete the target sum.

Given an array arr [] of integers and another integer target. You have to find all unique quadruples from the given array whose sum is equal to the given target. Note: All the quadruples should be internally …

In-depth solution and explanation for LeetCode 454. 4Sum II in Python, Java, C++ and more. Intuitions, example walk through, and complexity analysis. Better than official and forum solutions.

Can you solve this real interview question? 4Sum II - Given four integer arrays nums1, nums2, nums3, and nums4 all of length n, return the number of tuples (i, j, k, l) such that: * 0 <= i, j, k, l < n * nums1 …

Detailed solution explanation for LeetCode problem 18: 4Sum. Solutions in Python, Java, C++, JavaScript, and C#.

Problem Statement: Given an array of N integers, your task is to find unique quads that add up to give a target value. In short, you need to return an array of all the unique quadruplets [arr [a], arr [b], arr [c], …

Master the 4Sum problem with detailed solutions.