Minimum sum of two numbers formed from digits of an array Last Updated : 26 Mar, 2025 Comments Improve Suggest changes Like Article Like Report Try it on GfG Practice Given an array of digits (values are from 0 to 9), find the minimum possible sum of two numbers formed from digits of the array. All digits of given array must be used to form the two numbers.Examples: Input: arr[] = [6, 8, 4, 5, 2, 3]Output: 604Explanation: The minimum sum is formed by numbers 358 and 246Input: arr[] = [5, 3, 0, 7, 4]Output: 82Explanation: The minimum sum is formed by numbers 35 and 047 Min Heap-based Greedy Approach - O(n * log n) and O(n) spaceTo minimize the sum of two numbers formed by the digits of the array, we divide the digits into two halves and assign half of them to each number, ensuring the leading digits are smaller. We use a Min Heap to efficiently retrieve the two smallest elements at a time, appending them alternately to the two numbers. This process continues until all elements are exhausted. C++ #include <bits/stdc++.h> using namespace std; int minSum(vector<int> &arr) { // Create min heap priority_queue<int, vector<int>, greater<int>> pq(arr.begin(), arr.end()); string num1, num2; while (!pq.empty()) { num1 += to_string(pq.top()); pq.pop(); if (!pq.empty()) { num2 += to_string(pq.top()); pq.pop(); } } return stoi(num1) + stoi(num2); } int main() { vector<int> arr = {5, 3, 0, 7, 4}; cout << minSum(arr); } Java // Importing necessary libraries import java.util.PriorityQueue; public class MinSum { public static int minSum(int[] arr) { // Using a priority queue to simulate a min-heap PriorityQueue<Integer> minHeap = new PriorityQueue<>(); for (int num : arr) { minHeap.add(num); } StringBuilder num1 = new StringBuilder(); StringBuilder num2 = new StringBuilder(); while (!minHeap.isEmpty()) { num1.append(minHeap.poll()); if (!minHeap.isEmpty()) { num2.append(minHeap.poll()); } } return Integer.parseInt(num1.toString()) + Integer.parseInt(num2.toString()); } public static void main(String[] args) { int[] arr = {5, 3, 0, 7, 4}; System.out.println(minSum(arr)); } } Python import heapq def min_sum(arr): heapq.heapify(arr) num1, num2 = [], [] while arr: num1.append(str(heapq.heappop(arr))) if arr: num2.append(str(heapq.heappop(arr))) return int("".join(num1)) + int("".join(num2)) arr = [5, 3, 0, 7, 4] print(min_sum(arr)) C# // Importing necessary libraries using System; using System.Collections.Generic; public class MinSum { public static int MinSum(int[] arr) { // Using a priority queue to simulate a min-heap PriorityQueue<int, int> minHeap = new PriorityQueue<int, int>(); foreach (int num in arr) { minHeap.Enqueue(num, num); } string num1 = ""; string num2 = ""; while (minHeap.Count > 0) { num1 += minHeap.Dequeue(); if (minHeap.Count > 0) { num2 += minHeap.Dequeue(); } } return int.Parse(num1) + int.Parse(num2); } public static void Main(string[] args) { int[] arr = {5, 3, 0, 7, 4}; Console.WriteLine(MinSum(arr)); } } JavaScript // Import the heap module (not needed in JavaScript) function minSum(arr) { // Convert the array into a min-heap arr.sort((a, b) => a - b); let num1 = []; let num2 = []; while (arr.length > 0) { num1.push(arr.shift()); // Pop the smallest element if (arr.length > 0) { num2.push(arr.shift()); // Pop the next smallest element } } return parseInt(num1.join('')) + parseInt(num2.join('')); } const arr = [5, 3, 0, 7, 4]; console.log(minSum(arr)); Output82More Efficient Approaches :Please refer Minimum sum of two numbers formed from digits of an array for another O(n Log n) approach and a O(n) approach Comment More infoAdvertise with us Next Article Minimum sum of two numbers formed from digits of an array P Prakhar Improve Article Tags : Queue Greedy Mathematical Heap DSA Arrays number-digits +3 More Practice Tags : ArraysGreedyHeapMathematicalQueue +1 More Similar Reads Heap Data Structure A Heap is a complete binary tree data structure that satisfies the heap property: for every node, the value of its children is greater than or equal to its own value. 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