#include <iostream>
#include <iomanip>
#include <unordered_map>
#include <string>
#include <cstdlib>
using namespace std;


using hashUS = unordered_map<unsigned,string>;

// prototypes
hashUS::iterator getInteratorForName(hashUS&, const string& name);
ostream& operator<<(ostream&, const hashUS&);
unsigned rand100();


int main()
{
    hashUS students;

    using US = pair<unsigned,string>;

    students[rand100()] = "John";
    students.insert(US(rand100(),"Paul"));
    US george{rand100(),"George"};
    students.insert(george);
    auto ringo_num = rand100();
    US ringo{ringo_num,"Ringo"};
    students.insert(move(ringo));
    cout << students << endl;

    // What does this mean?
    students[50];
    cout << students << endl;

    // Try to insert a new element using Ringo's number
    students[ringo_num] = "Ringo Clone";
    cout << students << endl;

    // What is John's number?
    cout << "John's number is " <<
         getInteratorForName(students,"John")->first << endl;

    auto it = getInteratorForName(students,"maybe");
    if (it == students.end())
        cout << "maybe ain't there" << endl;

    cout << "number of elements with key " << ringo_num << " = "
         << students.count(ringo_num) << endl;
    cout << "number of elements with key " << ringo_num+1 << " = "
         << students.count(ringo_num+1) << endl << endl;

    cout << "students.bucket_count()=" << students.bucket_count() << endl;
}

unsigned rand100()
{
    return rand() % 100 + 1;
}

ostream& operator<<(ostream& out, const hashUS& obj)
{
    out << left;
    for (auto it = obj.begin(); it != obj.end(); ++it)
    {
        out << setw(5) << it->first << setw(10) << it->second << endl;
    }
    return out;
}

hashUS::iterator
getInteratorForName(hashUS& hash_us, const string& name)
{
    for (auto it = hash_us.begin(); it != hash_us.end(); ++it)
    {
        if (it->second == name)
            return it;
    }
    return hash_us.end();
}