[C/C++] unordered_map

#include <iostream>
#include <string>
#include <unordered_map>

using namespace std;

typedef unordered_map<string, string> stringmap;

stringmap merge(stringmap a, stringmap b)
{
    stringmap temp(a);
    temp.insert(b.begin(), b.end());
    return temp;
}

int main()
{
    stringmap first;
    stringmap second({ {"apple", "red"}, {"lemon", "yellow"} });
    stringmap third({ { "orange", "orange" },{ "strawberry", "red" } });
    stringmap fourth(second);
    stringmap fifth(merge(third, fourth));
    stringmap sixth(fifth.begin(), fifth.end());

    for (auto & x : sixth)
    {
        std::cout << " " << x.first << ":" << x.second;
    }
    std::cout << endl;

    return 0;
}

/*
mapped_type& at ( const key_type& k );
const mapped_type& at ( const key_type& k ) const;
Average case: constant.
Worst case: linear in container size.
*/
#include <iostream>
#include <string>
#include <unordered_map>

using namespace std;

int main()
{
    std::unordered_map<string, int> mymap = {
        {"Mars", 3000},
        {"Saturn", 60000},
        {"Jupiter", 70000}
    };

    mymap.at("Mars") = 3396;
    mymap.at("Saturn") += 272;
    mymap.at("Jupiter") = mymap.at("Saturn") + 9638;

    for (auto & x : mymap)
    {
        std::cout << x.first << ": " << x.second << std::endl;
    }

    return 0;
}

#include <iostream>
#include <string>
#include <unordered_map>

using namespace std;

int main()
{
    std::unordered_map<string, double> mymap = {
        {"milk", 2.30},
        {"potatoes", 1.90},
        {"eggs", 0.40}
    };

    std::cout << "mymap.size() is " << mymap.size() << std::endl;

    return 0;
}

#include <iostream>
#include <string>
#include <unordered_map>

using namespace std;

int main()
{
    unordered_map<string, string> mymap;
    mymap = {
        {"Australia", "Canberra"},
        {"U.S.", "Washington"},
        {"France", "Paris"}
    };

    std::cout << "mymap contains:";
    for (auto it = mymap.begin(); it != mymap.end(); ++it)
        cout << " " << it->first << ":" << it->second;
    cout << endl;

    cout << "mymap's buckets contains:\n";
    for (unsigned i = 0; i < mymap.bucket_count(); ++i)
    {
        cout << "bucket #" << i << " contains:";
        for (auto local_it = mymap.begin(i); local_it != mymap.end(i); ++local_it)
        {
            cout << " " << local_it->first << ":" << local_it->second;
        }
        cout << endl;
    }

    return 0;
}

#include <iostream>
#include <string>
#include <unordered_map>

using namespace std;

int main()
{
    unordered_map<string, string> mymap = {
        {"us", "United States"},
        {"uk", "United Kingdom"},
        {"fr", "France"},
        {"de", "Germany"}
    };

    for (auto & x : mymap)
    {
        cout << "Element [" << x.first << ":" << x.second << "]";
        cout << " is in bucket #" << mymap.bucket(x.first) << endl;
    }

    return 0;
}

#include <iostream>
#include <string>
#include <unordered_map>

using namespace std;

int main()
{
    unordered_map<string, string> mymap = {
        {"house", "maison"},
        {"apple", "pomme"},
        {"tree", "arbre"},
        {"book", "livre"},
        {"door", "porte"},
        {"grapefruit", "pamplemousse"}
    };

    unsigned n = mymap.bucket_count();

    cout << "mymap has " << n << " buckets.\n";

    for (unsigned i = 0; i < n; i++)
    {
        cout << "bucket #" << i << " contains: ";
        for (auto it = mymap.begin(i); it != mymap.end(i); ++it)
        {
            cout << "[" << it->first << ":" << it->second << "] ";
        }
        cout << endl;
    }

    return 0;
}

#include <iostream>
#include <string>
#include <unordered_map>

using namespace std;

int main()
{
    unordered_map<string, string> mymap = {
        {"us", "United States"},
        {"uk", "United Kingdom"},
        {"fr", "France"},
        {"de", "Germany"}
    };

    unsigned nbuckets = mymap.bucket_count();

    cout << "mymap has " << nbuckets << " buckets:\n";

    for (unsigned i = 0; i < nbuckets; i++)
    {
        cout << "bucket #" << i << " has " << mymap.bucket_size(i) << " elements.\n";
    }

    return 0;
}

#include <iostream>
#include <string>
#include <unordered_map>

using namespace std;

int main()
{
    unordered_map<string, double> myrecipe;
    unordered_map<string, double> mypantry = {
        {"milk", 2.0},
        {"flour", 1.5}
    };

    pair<string, double> myshopping("baking powder", 0.3);

    myrecipe.insert(myshopping);
    myrecipe.insert(std::make_pair<string, double>("eggs", 0.3));
    myrecipe.insert(mypantry.begin(), mypantry.end());
    myrecipe.insert({ {"sugar", 0.8}, {"salt", 0.1} });

    cout << "myrecipe contains:" << endl;
    for (auto & x : myrecipe)
    {
        cout << x.first << ": " << x.second << endl;
    }
    cout << endl;

    return 0;
}

#include <iostream>
#include <string>
#include <unordered_map>

using namespace std;

int main()
{
    unordered_map<string, double> mymap = {
        {"mom", 5.4},
        {"dad", 6.1},
        {"bro", 5.9}
    };

    string input;
    cout << "who? ";
    getline(std::cin, input);

    unordered_map<string, double>::const_iterator got = mymap.find(input);
    if (got == mymap.end())
        cout << "not found";
    else
        cout << got->first << " is " << got->second;

    cout << endl;

    return 0;
}