Find relative complement of two sorted arrays in C++

Suppose we have two sorted arrays arr1 and arr2, there sizes are m and n respectively. We have to find relative complement of two arrays. It means that we need to find all those elements which are present in arr1, but not in arr2. So if the arrays are like A = [3, 6, 10, 12, 15], and B = [1, 3, 5, 10, 16], then result will be [6, 12, 15]

To solve this, we can use the set_difference function. As the problem is basically set difference operation.

Example

 Live Demo

#include<iostream>
#include<algorithm>
#include<vector>
using namespace std;
int main() {
   int first[] = {3, 6, 10, 12, 15};
   int second[] = {1, 3, 5, 10, 16};
   int n = sizeof(first) / sizeof(first[0]);
   vector<int> temp(5);
   vector<int>::iterator it, ls;
   sort(first, first + 5);
   sort(second, second + 5);
   cout << "First array :";
   for (int i = 0; i < n; i++)
      cout << " " << first[i];
   cout << endl;
   cout << "Second array :";
   for (int i = 0; i < n; i++)
      cout << " " << second[i];
   cout << endl;
   ls = set_difference(first, first + 5, second, second + 5, temp.begin());
   cout << "The result of relative complement ";
   for (it = temp.begin(); it < ls; ++it)
      cout << " " << *it;
   cout << endl;
}

Output

First array : 3 6 10 12 15
Second array : 1 3 5 10 16
The result of relative complement 6 12 15

Arnab Chakraborty

Published on 17-Dec-2019 11:15:23

• Related Questions & Answers
• Median of Two Sorted Arrays in C++
• Merge two sorted arrays in C#
• Find the closest pair from two sorted arrays in c++
• Merge two sorted arrays using C++.
• K-th Element of Two Sorted Arrays in C++
• Merge two sorted arrays in Java
• JavaScript Program for find common elements in two sorted arrays
• C++ Program to find the median of two sorted arrays using binary search approach
• C/C++ Program for Median of two sorted arrays of same size?
• Merging two unsorted arrays in sorted order in C++.
• Sorted Arrays in C++
• C# program to merge two sorted arrays into one
• Merge two sorted arrays into a list using C#
• Find common elements in three sorted arrays in C++
• Intersection of Three Sorted Arrays in C++