Map_stl.cpp

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

using namespace std;

int main()
{
    
    // empty map container
    map<int, int> gquiz1;
    
    // 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>(7, 10));
    
    // printing map gquiz1
    map<int, int>::iterator itr;
    cout << "\nThe map 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
    map<int, int> gquiz2(gquiz1.begin(), gquiz1.end());
    
    // print all elements of the map gquiz2
    cout << "\nThe map 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 key=3 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 map 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;
}

//Multimap is similar to map with an addition that multiple elements can have same keys. Also, it is NOT required that the key value and mapped value pair has to be unique in this case.