Union of Two Arrays with Distinct Elements

Summary

Given two arrays arr1 and arr2, write a program to find their union. The union of two sets is the set of all elements that are in either set, without duplicates.

Detailed Explanation

To solve this problem, we can iterate through both arrays and add each element to a new array, ensuring that duplicate elements are not included.

Here's the step-by-step breakdown:

Create an empty array result to store the union.
Iterate through arr1. For each element x, check if it already exists in result. If not, add x to result.
Repeat step 2 for arr2.
Return the resulting array.

Here's an ASCII art diagram of the process:

  arr1: [1, 2, 3]
  arr2: [2, 4, 5]

  result = []
  foreach x in arr1
    if !result.contains(x) then add x to result

  result = [1, 2, 3]
  foreach y in arr2
    if !result.contains(y) then add y to result

  result = [1, 2, 3, 4, 5]

The time complexity of this solution is O(n), where n is the total number of elements in both arrays. The space complexity is also O(n), as we need to store all distinct elements in the result array.

Optimized Solutions

Java

public int[] union(int[] arr1, int[] arr2) { Set<Integer> set = new HashSet<>(); for (int x : arr1) { if (!set.contains(x)) { set.add(x); } } for (int y : arr2) { if (!set.contains(y)) { set.add(y); } } int[] result = new int[set.size()]; int i = 0; for (int x : set) { result[i++] = x; } return result; }