Merge operations using STL in C++ | merge(), includes(), set_union(), set_intersection(), set_difference(), inplace_merge

In this tutorial, we will be discussing a program to understand the various merge operations using STL in C++.

The merge() function is used to merge two sorted containers in a way that the new container is also sorted. Further includes() is used to check if the elements from first container are present in the second one.

Example

#include<iostream>
#include<algorithm>
#include<vector>
using namespace std;
int main(){
   vector<int> v1 = {1, 3, 4, 5, 20, 30};
   vector<int> v2 = {1, 5, 6, 7, 25, 30};
   //initializing resultant vector
   vector<int> v3(12);
   merge(v1.begin(), v1.end(), v2.begin(),
   v2.end(), v3.begin());
   cout << "The new container after merging is :\n";
   for (int &x : v3)
      cout << x << " ";
   cout << endl;
   vector<int> v4 = {1, 3, 4, 5, 6, 20, 25, 30};
   includes(v4.begin(), v4.end(), v1.begin(), v1.end())?
      cout << "v4 includes v1":
      cout << "v4 does'nt include v1";
   return 0;
}

Output

The new container after merging is :
1 1 3 4 5 5 6 7 20 25 30 30
v4 includes v1