associative container data structure in c++

Hi,
I am trying to implement a student grading system.
-Use an Associative container, multimap.
-Search record by Student name (the key) and the data consists of student ID and GPA.
Since more than one student can have the same name, use a
multimap.

progam does the following:
1. It will use a multimap as the container.
2. It will use the Student class to describe the
ID and GPA. multimap will be declared:
multimap<string, Student> grades;
3. use data(names, IDs and GPAs)
4. The main() driver will display a menu of commands available to
the user: The commands are:
a. insert a student’s data into the system, The program will
allow duplicate names to be inserted.
b. Find a student’s data, given the student’s name(key). If
there are multiple students in the container with the given
name, display information about all of them.
c.. Exit the system

1. should have a source (.h and .cpp) files



please help thanks

 

how i stated:

Code:

#include <iostream>
#include <string>
#include <map>
using namespace std;

class Student
{
public:
  //--- Constructor
  Student (int id = 0, double gpa = 0);
  //--- Output operator
  friend ostream & operator<<(ostream & out, const Student & s);
  //--- Input operator
  friend istream & operator>>(istream & in, Student & s);
  //--- Less-than operator
  friend bool operator<(const Student & a, const Student & b);
private:
  //--- Data members
  int myId;
  double myGPA;
};  // end of class Student

//--- Definition of constructor
inline Student::Student(int id, double gpa)
  : myId(id), myGPA(gpa)
{ }

//--- Definition of input operator
inline istream & operator>>(istream & in, Student & s)
{
  in >> s.myId >> s.myGPA;
  
}

//--- Definition of output operator
inline ostream & operator<<(ostream & out, const Student & s)
{ out << "id = " << s.myId << "  GPA = " << s.myGPA;
 return out;
}

//--- Definition of less-than operator
inline bool operator<(const Student & a, const Student & b)
{ return a.myId < b.myId; }
//================================================================

int main()
{
	//typedef multimap<string, Student>grades
  typedef multimap<string, Student, less<string>> grades1;
  typedef multimap<Student, string, less<Student>> grades2;

  grades1 a1;   // associative array of Student, index type is string
  grades2 a2;   // associative array of string, index type is Student

  Student s;
  s = Student(12345, 3.3);  a1["Fred"] = s;   a2[s] = "Fred";
  s = Student(32322, 3.9);  a1["Al"] = s;     a2[s] = "Al";
  s = Student(13131, 2.5);  a1["Joan"] = s;   a2[s] = "Joan";
  s = Student(22121, 4.0);  a1["Barb"] = s;   a2[s] = "Barb";
  s = Student(28888, 2.9);  a1["George"] = s; a2[s] = "George";
  s = Student(19981, 3.0);  a1["Dot"] = s;    a2[s] = "Dot";
  s = Student(20012, 2.9);  a1["Sue"] = s;    a2[s] = "Sue";
  string name;
  cout << "Enter a name: ";
  cin >> name;
  grades1::iterator it1 = a1.find(name);
  cout << name << " has ";
  if (it1 == a1.end())
    cout << "no info";
  else
    cout << a1[name];
  cout << endl;

  Student aStudent;
  cout << "Enter a Student's id and GPA: ";
  cin >> aStudent;
  grades2::iterator it2 = a2.find(aStudent);
  cout << "Student " << aStudent << " is ";

  if (it2 == a2.end())
    cout << "no info";
  else
    cout << a2[aStudent];
  cout << endl;

}

 

OK, what do you need help with? You've written some fairly advanced stuff there with friends and operators and so on, so the whole task should be straight forward for you.