Combination of numbers that equal a given sum java. 46 I have a list of numbers, e.

Combination of numbers that equal a given sum java. It is guaranteed that the number of unique combinations that sum up to target is less than 150 combinations for the given input. Nov 25, 2017 · Two combinations are unique if the frequency of at least one of the chosen numbers is different. May 20, 2025 · Continue this process until the size of the current combination becomes equal to r. For example, if we are given input ‘5’, these are the possible sum combinations. 1 2 3 How many unique combinations will we have if we cannot repeat Jul 29, 2024 · I am trying to iterate over all possible combinations of integers with a given sum and size, in order to find the item with the lowest standard deviation. 8K subscribers Subscribed Jan 14, 2017 · You are given a number n. Feb 13, 2025 · Our goal is to find all unique combinations where the chosen numbers sum to the target. If you are interested in related problems (with sum of more than 2 numbers), see "Sum-subset with a fixed subset size" and "Finding three elements in an array whose sum is closest to an given number". Oct 1, 2022 · I'm working on the following problem: Given an array of integers and a sum B, find all unique combinations in the array where the sum is equal to B. In one operation, you can pick two numbers from the array whose sum equals k and remove them from the array. Aug 11, 2024 · Print All Possible Number Combinations Whose Sum is 10: The program InterviewPrograms55 aims to find pairs of numbers in a given sequence that add up to 10. asList (new Integer [] {15, 12, 4, 16, 9, 8 Can you solve this real interview question? Max Number of K-Sum Pairs - You are given an integer array nums and an integer k. It prepares a temporary storage (tempCombo) for current combinations and a container (allCombos) to hold all valid combinations. The same number may be chosen from the array any Combination Sum II - Given a collection of candidate numbers (candidates) and a target number (target), find all unique combinations in candidates where the candidate numbers sum to target. ” This problem tests a developer’s ability to find all possible combinations of elements in a given array that add up to a specific target value. Using these observations, we can generate all the unique combinations that sum up to the given target. Example 2 Jun 22, 2023 · Combination Sum Let’s start with the first problem, Combination Sum. When shopping, you can also choose combinations that add up to a total. I was asked about this program in an interview. Overview In this quick tutorial, we’ll show how to implement an algorithm for finding all pairs of numbers in an array whose sum equals a given number. ---This video is based on the question http It combines multiple numbers and calculates and displays combinations whose total equals the total value entered. Feb 15, 2022 · Finding all possible combinations of numbers of an array to reach a given sum Asked 3 years, 5 months ago Modified 3 years, 5 months ago Viewed 1k times May 13, 2025 · Java programming exercises and solution: Write a Java program that accepts an even number (n should be greater than or equal to 4 and less than or equal to 50,000, a Goldbach number) from the user and creates combinations that express the given number as a sum of two prime numbers. Examples of Combinations Combinations without repetitions Let's say that we wanted to pick 2 balls out of a bag of 3 balls colored red (R), green (G) and purple (P). Key points about this problem: Numbers can be reused: You can use the same number from candidates multiple times in a single combination. Two combinations are unique if the Mar 27, 2024 · This blog discusses the method to find all the combinations of given numbers such that the sum is equal to a given number. Exam Mar 11, 2012 · Space complexity is O (1). I am trying to find out if any combination of elements in the array sums to a specific size or not. Write a program using recursion which finds all the possible combinations of numbers whose sum is equal to n. Is there a way in Java or any other language to optimally/quickly find a subset of these numbers that could some up to a given target sum or if it's not possible to find the subset that gives the closest sum to the target sum? 4 days ago · Learn how to efficiently find combinations of numbers from specified ranges that add up to a given sum using Java. We can return quadruplets in any order, but all the quadruplets should be internally sorted, i. May 9, 2025 · Java array exercises and solution: Write a Java program to find all combinations of four elements of an array whose sum is equal to a given value. Click on Go, then wait for combinations to load. Only numbers from 1 to 9 can be used, and each number may appear at most once in a combination. Learn how to find all possible combinations of integers that add up to a specific number with clear explanations and code examples. May 12, 2025 · The provided C++ solution defines a method to find all possible combinations of numbers from a given set (candidates) that sum up to a specified goal. The idea is to consider every integer i from 1 to n and add it to the output and recur for remaining elements [i…n] with reduced sum n-i. The sum can be made from some of these numbers and sometimes cannot be made. A number x from the list is given ,we need to find any two numbers in the list having sum equal to x. Combinations are valid such that two combinations have different subset of elements. For example: Looking to find all 3-number combos whose sum = 3 Desired Output: [0,0,3], [0,3 The Combination Sum Calculator finds all possible combinations of numbers that add up to a target sum. It takes an input array of integers and looks for all combinations of two numbers whose sum is equal to 10. how can we improve the logic? List<Integer> listOfNumbers = Arrays. For each element in the list, the algorithm checks all the remaining elements in the list to find a pair whose sum is equal to the given sum. Mar 15, 2022 · How to get all combination for a given sum with a given number of elements Asked 3 years, 3 months ago Modified 3 years, 2 months ago Viewed 3k times Jun 19, 2013 · Given an unknown amount of lists, each with an unknown length, I need to generate a singular list with all possible unique combinations. Mar 27, 2024 · Now, we are given a number, and we have to find all possible combinations of the numbers in the array such that the sum of the combination is equal to the given number. Otherwise, return false. Example 1: Input: n = 4, k = 2 Output: [[1,2],[1,3],[1,4],[2,3],[2,4],[3,4]] Explanation: There are 4 choose 2 = 6 total combinations. The list must not contain the same combination twice, and the combinations may be returned in any order Jul 15, 2025 · After finding the minimum number of coins use the Backtracking Technique to track down the coins used, to make the sum equals to X. Given three integers n, k, and target, you need to find the number of possible ways to roll all the dice such that the sum of the face-up numbers equals exactly target. Your task is to find all unique combinations of numbers from candidates that sum up to target. Given two integers n and k, return all possible combinations of k numbers chosen from the range [1, n]. For example, if candidates = [2, 3, 5] and target Jun 27, 2023 · Problem Statement Given an array, a [], consisting of distinct elements, and a target sum, find all the unique combinations in the array where the sum is equal to the target sum. You may return the combinations in any order How to find 3 numbers in all combinations possible that in a sum the result equals n? Asked 11 years ago Modified 8 years, 4 months ago Viewed 4k times May 11, 2023 · Method#5: Using nested loops Approach this approach is a brute-force approach that uses nested loops to iterate through each element in the list and find all possible pairs that add up to the given sum. Oct 24, 2023 · Problem Statement Combination Sum (LeetCode #39): Given an array of distinct integers candidates and a target integer target, return a list of all unique combinations of candidates where the May 13, 2025 · Java programming exercises and solution: Write a Java program to find all unique combinations from a collection of candidate numbers. In the first approach, we’ll find all such pairs regardless of uniqueness. Nov 13, 2015 · I want to find all the pairs of numbers from an array whose sum is equal to 10, and am trying to improve upon this bit of code here: for (int j = 0; j &lt; arrayOfIntegers. For example if the array is [1,1,1,2,4,4] and the given target is 5 then should the output be: Expected Output 1 1 1 2 1 4 1 4 Aug 24, 2021 · How would you find all the integer (excluding negative) combinations of a given number without a given set of numbers? I would imagine it most similar to finding solutions to a stars and bars problem. The specific requirements are: Jul 2, 2025 · Given two integer arrays a [] and b [] of the same length, and an positive integer k, the goal is to find the top k maximum sum combinations, where each combination is formed by adding one element from a and one from b. , [1,2] and [2,1] are considered to be the same combination. Note: Each element in the array can be used at most once in the combination. Running time must be less than n^2. In this article, we’ll solve this problem using recursion with Sep 26, 2025 · Given an array arr [] of integers and an integer target, find all unique combinations of elements where the sum of the chosen elements is equal to target. Then click on 'download' to download all combinations as a txt file. For example: if input is 15, then the consecutive numbers that sum upto 15 are: 1,2,3,4,5 4,5,6 7,8 So the answer is 3 as we have 3 possibilities here. Below is the method for how this solution is structured: The combinationSum function initializes the process. Example: Input: N = 7, K = 3 Output: 15 Sep 26, 2025 · Given two integers, n and k, find all possible unique combinations of k numbers whose sum equals n. Dec 26, 2022 · Given a collection of candidate numbers (candidates) and a target number (target), find all unique combinations in candidates where the candidate numbers sum to target. Can you solve this real interview question? Combination Sum - Given an array of distinct integers candidates and a target integer target, return a list of all unique combinations of candidates where the chosen numbers sum to target. This represents a valid way to form the target sum. Jul 23, 2025 · If the target sum is reached (i. Apr 6, 2023 · Given an array of distinct integers candidates and a target integer target, return a list of all unique combinations of candidates where the chosen numbers sum to target. GeeksforGeeks | A computer science portal for geeks Aug 5, 2025 · In the Combination problem we are given an array of integers and a target number, we have to return all unique possible combinations whose element sum is equal to the target value. In the above solution, it is possible to get all the combinations without repeating the same number using given set of numbers to sum up to the given value. 46 I have a list of numbers, e. Below are the steps: Let findWays () be the required answer for sum N. , for any quadruplets [q1, q2, q3, q4] the following should follow: q1 <= q2 <= q3 <= q4. Jul 11, 2023 · I have tried to find the sum of pair which is equals to given number using Java 8. Jul 23, 2025 · Given a number N. Each number can only be used Dec 12, 2022 · How To Use Python to find combinations of value with equal or greater than given sum? Asked 2 years, 5 months ago Modified 2 years, 5 months ago Viewed 806 times Aug 22, 2023 · Combination Sum Problem Statement Given a list of integers and a target integer, we have to return a list of all unique combinations of candidates where the chosen numbers sum to the target. e. Return a list of all possible valid combinations. numbers = [1, 2, 3, 7, 7, 9, 10] As you can see, numbers may appear more than once in this list. May 17, 2019 · Finding all possible combinations of numbers to reach a given sum. 10. . g. Since there are k^n total possible outcomes when rolling n dice (each die can show one of k faces), you're counting how many of these outcomes sum to the target value. Print the number of combinations. The May 13, 2025 · If the combination is valid (sum equals n and contains exactly k numbers), record it. The same number may be chosen from the list an unlimited number of times. The task is to print all possible consecutive numbers that add up to N. Feb 3, 2019 · 14 I was going through a simple program that takes a number and finds the number of occurrences of consecutive numbers that matches with given number. Question. Following is the C, C++, Java, and I want to finding all combinations in an array to reach a given sum. We can use any number multiple times. The same number may be chosen from candidates an unlimited number of times. May 3, 2017 · Given a set of numbers: {1, 3, 2, 5, 4, 9}, find the number of subsets that sum to a particular value (say, 9 for this example). For each element, we reduce the target by its value and continue the process recursively. Jul 15, 2025 · Recursive Approach: The idea is to iterate for every possible value of dice to get the required sum N. Oct 8, 2023 · Understanding Combination Sum Combination Sum problems involve finding combinations of elements from a given set that add up to a specific target value. Combination Sum Given a set of candidate numbers (candidates) (without duplicates) and a target number (target), find all unique combinations in candidates where the candidate numbers sums to target. If the sum is equal to target, return true. Note: The solution set must not contain duplicate combinations. If the sum exceeds n or more than k numbers are included, backtrack by removing the last added number and try the next available number. This calculator is helpful in solving mathematical problems, programming challenges, or decision-making scenarios where a specific sum needs to be achieved using a given set of numbers. Note: All numbers (including target) will be positive integers. Examples : Input: N = 100 Output: 9 10 11 12 13 14 15 16 18 19 20 21 22 GeeksforGeeks | A computer science portal for geeks Mar 23, 2020 · I'm trying to find the most efficient way to find all combinations of numbers that equal a given sum. For example, given the following lists: X: [A, B, C] Y: [W Sep 20, 2021 · I have an array of numbers say [1,2,3,1,1000] , now I want to get all possible combinations of this array and calculate its sum. Learn how to finding consecutive numbers sum equal to natural numbers. Store the chosen coin in an array. Question: Given an unsorted array of positive integers, is it possible to find a pair of integers from that array that sum up to a given sum? Oct 11, 2016 · I am trying to solve a problem with numbers: I receive a number and have to calculate the numbers that add up to get that number, there are some rules that make it harder Rules: Positive numbers Number of Dice Rolls With Target Sum - You have n dice, and each dice has k faces numbered from 1 to k. Combination Sum Description Given an array of distinct integers candidates and a target integer target, return a list of all unique combinations of candidates where the chosen numbers sum to target. The only numbers obtained from the throw of dice are [1, 6], each having equal probability in a single throw of dice. This is similar to subset sum problem with the slight difference that May 14, 2024 · Problem Overview: Understand the essence of the Combination Sum problem, which involves finding all unique combinations in a set of candidates that sum up to a given target value. If radix sort is used, complexities of the whole algorithm are the same. Two combinations are unique if the Jan 8, 2011 · How would you go about testing all possible combinations of additions from a given set N of numbers so they add up to a given final number? A brief example: Set of numbers to add: N = {1,5,22,15,0 Problem Description You are given an array of distinct integers called candidates and a target integer target. Oct 8, 2019 · Find All Pairs of Numbers in an Array That Add Up to a Given Sum 1. Note that combinations are unordered, i. Given three integers n, k, and target, return the number of possible ways (out of the kn total ways) to roll the dice, so the sum of the face-up numbers equals target. So my questions is: what is the correct approach to solve this problem, given that order matters? May 11, 2024 · We also used these methods to calculate the sum of values of a given field of a list of objects, the sum of the values of a map, and the numbers within a given String object. See full list on baeldung. Sample Test Cases : Input 1: a [] = [1, 2], sum = 4 Problem Statement Given a positive integer, target, print all possible combinations of positive integers that sum up to the target number. We’ll focus on two approaches to the problem. com Oct 3, 2025 · The idea is to explore all possible combinations of numbers that add up to the target. This problem seems to be different than this one: Finding all possible combinations of numbers to reach a given sum. Jul 30, 2013 · With a list of about 60 numbers, it seems to find a dozen or more combinations for any total that's reasonable. Algorithmic Approach: Dive into the algorithmic strategies used to tackle the Combination Sum problem, including backtracking and depth-first search (DFS). Aug 13, 2025 · [Naive Approach] Generating All Triplets - O (n^3) Time and O (1) Space A simple method is to generate all possible triplets and compare the sum of every triplet with the given target. You may return the answer in any order. Jan 18, 2025 · Problem Statement Link - Problem 39 Question Given an array of distinct integers candidates and a target integer target, return a list of all unique combinations of candidates where the chosen numbers sum to target. For example x1+x2+x3+x4+x5++etc=n, where x1 Enter a custom list Get Random Combinations It may take a while to generate large number of combinations. Given an array of distinct integers (candidates) and a target integer (target), the goal Write a java program that will display consecutive natural numbers whose sum equal to input numbers. Jan 8, 2016 · Welcome to Subscribe On Youtube 39. This problem allows for repetition, so we’re going to solve it using a recursive backtracking strategy. Is there a math principle that describes why this is? Supposing, there is a list of numbers (whole numbers, decimal numbers or negative numbers), and now, you want to find all possible combinations from these numbers that equal a given sum. Note that this approach requires us to have a list of indices where a particular element occurs. The task is given an integer array as input and another number say target, find all possible combinations in array that sum up to given target. Combinations Calculator What is a Combination? A combination is a selection of r items from a set of n items such that we don't care about the order of selection. The same repeated number may be chosen from candidates unlimited number of times. All possible combinati May 29, 2022 · Ep11- Combinations | Find all possible combinations of k numbers out of the range 1 to N | Recursion LearnYard 65. Mar 27, 2024 · This blog finds all possible combinations of K numbers that sum to N. I was expecting a single combination to satisfy my total, or maybe a few possibilities, but there always seem to be a ton of combinations. Apr 28, 2015 · 1 I have an array with positive integers in random order. For example, if sum=4 and the size=2 then these are all the possible combinations of integers: Jul 23, 2025 · Given a positive number, find out all combinations of positive numbers that adds upto that number. Given an array of distinct integers candidates and a target integer target, return a list of all unique combinations of candidates where the chosen numbers sum to target. To avoid printing permutations, each combination will be constructed in non-decreasing order. I need to get all combinations of these numbers that have a given sum, e. Java programming exercises and solution: Write a Java program to find all unique combinations from a collection of candidate numbers. The task is: Given an array A of size N, find all combinations of four elements in the array whose sum is equal to a given value K. The program should print only combinations, not permutations. You may return the combinations in any order. Enter the sum in the first box and the numbers in the second box. Since the answer may be too large, return it modulo 109 + 7. Jul 23, 2025 · Given a number N, the task is to count the combinations of K numbers from 1 to N having a sum equal to N, with duplicates allowed. Dec 25, 2022 · Given an array of distinct integers candidates and a target integer target, return a list of all unique combinations of candidates where the chosen numbers sum to target. Return the maximum number of operations you can perform on the array. We discuss the problem statement in detail, provide an example solution in JavaScript & Java, and discuss some key insights and tips for solving 39. Nov 22, 2010 · I am trying to implement a coin problem, Problem specification is like this Create a function to count all possible combination of coins which can be used for given amount. At each recursive call, iterate from the current start index to the end of the array while ensuring there are enough remaining elements to fill the combination. length - 1; j++) { Jul 23, 2025 · [Naive Approach] Using Three Nested Loops - O (n^3) Time and O (1) Space The simplest approach is to generate all possible triplets using three nested loops and if the sum of any triplet is equal to zero then add it to the result. Can you solve this real interview question? Combination Sum III - Find all valid combinations of k numbers that sum up to n such that the following conditions are true: * Only numbers 1 through 9 are used. , s becomes equal to target sum) and all elements in the array have been processed, return 1. The same number from the array may be chosen any number of times. Combination Sum Calculator Find all combinations from a given set of numbers that add up to a given sum. If a combination with the given sum is reached, print it. Read to learn more. May 10, 2024 · Given an array of integers arr, the length of the array n, and an integer k, find all the unique combinations in arr where the sum of the combination is equal to k. Each number in candidates may only be used once in the combination. Two combinations are unique if the Jan 12, 2025 · The Combination Sum problem is a classic algorithmic challenge that demonstrates the power of backtracking. * Each number is used at most once. In backtracking, traverse the array and choose a coin which is smaller than the current sum such that dp [current_sum] equals to dp [current_sum - chosen_coin]+1. Oct 13, 2022 · In this post, we explore a classic coding challenge from Leetcode: problem 39, “Combination Sum. Can you solve this real interview question? Consecutive Numbers Sum - Given an integer n, return the number of ways you can write n as the sum of consecutive positive integers. The sum of the numbers will be equal to a given target number. Sep 12, 2025 · Practice this problem We can use recursion to solve this problem. The sum of the numbers will equal a given target number. We can return the combinations in any order. Read the blog to learn the problem's implementation in detail. Aug 13, 2025 · Given an array arr [], and an integer target, find all possible unique quadruplets in an array whose sum is equal to the given target value. mvr e0b 3ez4z vysh zgy qyyx ld2da j0xrae qv5k d7rc