C++ Pair Template in STL Program

Hello Everyone!

In this tutorial, we will learn about the working of a Pair Template its implementation using a Vector in the C++ programming language.

To understand the basic functionality of the Pair Template, we will recommend you visit C++ STL Pair Template, where we have explained this concept in detail from scratch.

For a better understanding of its implementation, refer to the well-commented C++ code given below.

Code:

#include <iostream>
#include <bits/stdc++.h>

using namespace std;

int main()
{
    cout << "\n\nWelcome to Studytonight :-)\n\n\n";
    cout << " =====  Program to demonstrate the working of a Pair Template in STL, in CPP  ===== \n\n";

    cout << "\n\nDeclaring a Vector and Filling it with pair of two integers.\n\n";

    //create an empty vector of pair
    vector<pair<int, int>> v;

    //insert elements into the vector
    v.push_back(make_pair(8, 64));
    v.push_back(make_pair(1, 1));
    v.push_back(make_pair(3, 6));
    v.push_back(make_pair(2, 4));
    v.push_back(make_pair(5, 25));

    //prining the vector of pairs
    cout << "Printing the Vector of Pairs: \n";

    int n = v.size();

    //Printing the vector
    for (int i = 0; i < n; i++)
    {
        cout << "\nSquare of " << v[i].first << " is " << v[i].second; //accessing the pair elements
    }

    //Sorting the vector in ascending order - by default on the basis of first element of the pair
    sort(v.begin(), v.end());

    cout << "\n\n\n\nThe elements of the Vector after Sorting are:\n ";

    //prining the Sorted vector
    for (int i = 0; i < n; i++)
    {
        cout << "\nSquare of " << v[i].first << " is " << v[i].second; //accessing the pair elements
    }

    cout << "\n\n\n";

    return 0;
}

Output:

We hope that this post helped you develop a better understanding of the concept of the Pair Template and its implementation in CPP. For any query, feel free to reach out to us via the comments section down below.

Keep Learning : )