multi_map.cpp

#include <iostream>
#include <map>
#include <iterator>

using namespace std;

int main()
{
    multimap <int, int> gquiz1;     // empty multimap container
    
    // insert elements in random order
    gquiz1.insert(pair <int, int> (1, 40));
    gquiz1.insert(pair <int, int> (2, 30));
    gquiz1.insert(pair <int, int> (3, 60));
    gquiz1.insert(pair <int, int> (4, 20));
    gquiz1.insert(pair <int, int> (5, 50));
    gquiz1.insert(pair <int, int> (6, 50));
    gquiz1.insert(pair <int, int> (6, 10));
    
    // printing multimap gquiz1
    multimap <int, int> :: iterator itr;
    cout << "\nThe multimap gquiz1 is : \n";
    cout << "\tKEY\tELEMENT\n";
    for (itr = gquiz1.begin(); itr != gquiz1.end(); ++itr)
    {
        cout << '\t' << itr->first
        << '\t' << itr->second << '\n';
    }
    cout << endl;
    
    // assigning the elements from gquiz1 to gquiz2
    multimap <int, int> gquiz2(gquiz1.begin(),gquiz1.end());
    
    // print all elements of the multimap gquiz2
    cout << "\nThe multimap gquiz2 after assign from gquiz1 is : \n";
    cout << "\tKEY\tELEMENT\n";
    for (itr = gquiz2.begin(); itr != gquiz2.end(); ++itr)
    {
        cout << '\t' << itr->first
        << '\t' << itr->second << '\n';
    }
    cout << endl;
    
    // remove all elements up to element with value 30 in gquiz2
    cout << "\ngquiz2 after removal of elements less than key=3 : \n";
    cout << "\tKEY\tELEMENT\n";
    gquiz2.erase(gquiz2.begin(), gquiz2.find(3));
    for (itr = gquiz2.begin(); itr != gquiz2.end(); ++itr)
    {
        cout << '\t' << itr->first
        << '\t' << itr->second << '\n';
    }
    
    // remove all elements with key = 4
    int num;
    num = gquiz2.erase(4);
    cout << "\ngquiz2.erase(4) : ";
    cout << num << " removed \n" ;
    cout << "\tKEY\tELEMENT\n";
    for (itr = gquiz2.begin(); itr != gquiz2.end(); ++itr)
    {
        cout << '\t' << itr->first
        << '\t' << itr->second << '\n';
    }
    
    cout << endl;
    
    //lower bound and upper bound for multimap gquiz1 key = 5
    cout << "gquiz1.lower_bound(5) : " << "\tKEY = ";
    cout << gquiz1.lower_bound(5)->first << '\t';
    cout << "\tELEMENT = " << gquiz1.lower_bound(5)->second << endl;
    cout << "gquiz1.upper_bound(5) : " << "\tKEY = ";
    cout << gquiz1.upper_bound(5)->first << '\t';
    cout << "\tELEMENT = " << gquiz1.upper_bound(5)->second << endl;
    
    return 0;
    
}