Help with structures

[kylet]

I am very confused with structures. I do not fully understand the terminology in the comments, and am completely lost with what I am doing wrong, mainly with things labeled/related to Objective 3(a,b,c). Any help is much appreciated.

#include<iostream>
#include<iomanip>
#include<string>
#include<cctype>
using namespace std;

// Named constants for vehicle category

const string CARPOOL = "Carpool",
             FAMILY = "Family",
             SPORT = "Sport";

// TODO (Objective 1):	Replace named constants for capacity groupings with
//						the required CapacityGroup enumeration

enum CapacityGroup {CG_ERR, CG_1_2, CG_3_4, CG_5_6, CG_7_8, CG_9_12};

// Named constants for seating capacity groupings


// TODO (Objective 2):	Define the required Vehicle structure with two fields

//          category:       type string
//          occupants:      type int

struct Vehicle
{
	string category;
	int occupants;
};



// function prototype declarations
void DisplayResults(string category, int occupants);

// TODO (Objective 3a): Replace string and int paramters with 1 Vehicle structure type
Vehicle GetRecommendation(Vehicle f1);


// OPTIONAL (Idea 1a): Change return type to CapacityGroup
int GetCapacityGroup(int occupants);


// OPTIONAL (Idea 2a): Change parameter type to CapacityGroup
string GetCarpoolRecommendation(int group);
string GetFamilyRecommendation(int group);
string GetSportRecommendation(int group);




int main()
{
    /*
        DO NOT MODIFY the main() function block!
    */

    cout << endl
         << "------------------------------------------------------" << endl
         << "This program recommends a vehicle based on its purpose" << endl
         << "and the seating capacity for expected occupants." << endl
         << "------------------------------------------------------" << endl
         << endl;

    // Test Carpool category.

    cout << CARPOOL << ":" << endl;

    for(int occupants = 13; occupants >= 0; occupants--)
        DisplayResults(CARPOOL, occupants);

    cout << endl;

      // Test Family category.

    cout << FAMILY << ":" << endl;

    for(int occupants = 13; occupants >= 0; occupants--)
        DisplayResults(FAMILY, occupants);

    cout << endl;

      // Test Sport category.

    cout << SPORT << ":" << endl;

    for(int occupants = 13; occupants >= 0; occupants--)
        DisplayResults(SPORT, occupants);

    cout << endl;

      // Test unknown and not specified category

    cout << "Other:" << endl;

    DisplayResults("Vacation", 5);          // category unknown
    DisplayResults("", -1);                 // category not specified

    cout << endl << "- End Program - " << endl;
}

//------------------------------------------------------------------------------

// Function definitions

  /*  Function: DisplayResults(string category, int occupants)

      Prints occupants, and then gets and prints a recommendation.

      Parameters:

      category - incoming: A string for identifying purpose of vehicle.
      occupants - incoming: An integer indicating how many occupants are expected.

      Return value: None.
  */
void DisplayResults(string category, int occupants)
{
    // TODO (Objective 3c): Declare Vehicle structure variable

	Vehicle f1;

    // TODO (Objective 3c): Initialize Vehicle fields with function parameter values

	f1.category = category;
	f1.occupants = occupants;

    // TODO (Objective 3c): Replace function call arguments with 1 Vehicle structure variable
    string recommendation = Vehicle f1;



    cout << setw(12) << occupants << " occupants - "
         << recommendation << endl;
}

//------------------------------------------------------------------------------

/*
  Gets a capacity grouping designation based on number of occupants.

  POST CONDITION: return value is in range 1-12
  with invalid values designated CG_ERR
*/
// OPTIONAL (Idea 1a): Change return type to CapacityGroup
int GetCapacityGroup(int occupants)
{
    // OPTIONAL (Idea 1b): Change variable type to match function return type
    int group;


    if( occupants < 1 || occupants > 12 )   // invalid
        group = CG_ERR;
    else if( occupants >= 9 )               // 9-12
        group = CG_9_12;
    else if( occupants >= 7 )               // 7-8
        group = CG_7_8;
    else if( occupants >= 5 )               // 5-6
        group = CG_5_6;
    else if( occupants >= 3 )               // 3-4
        group = CG_3_4;
    else                                    // 1-2
        group = CG_1_2;

    return group;
}

//------------------------------------------------------------------------------

/*
  Gets a vehicle recommendation based on the category and number of
  occupants.

  POST CONDITION: return value is a vehicle recommendation or other message.
*/
// TODO (Objective 3a): Replace string and int parameters with 1 Vehicle parameter
Vehicle GetRecommendation(Vehicle f1)
{
    // TODO (Objective 3b): Use Vehicle fields where necessary in place of
    //						string and int parameters.
    // NOTE:				Should require 4 modifications


    // OPTIONAL (Ideas 1c/2b): Change variable type to match function return type
    // Get the capacity group for the occupants parameter.

    int group = GetCapacityGroup(f1.occupants);




    string recommendation;

    // Compare the category parameter to string constants.

    if( fcategory == CARPOOL )
    {
      recommendation = GetCarpoolRecommendation(group);
    }
    else if( category == FAMILY )
    {
      recommendation = GetFamilyRecommendation(group);
    }
    else if( category == SPORT )
    {
      recommendation = GetSportRecommendation(group);
    }
    else
    {
      recommendation = "Purpose unknown or not specified.";
    }

    return recommendation;
}

//------------------------------------------------------------------------------

/*
  Gets a vehicle recommendation for CARPOOL category based on the capacity grouping.

  POST CONDITION: return value is a vehicle recommended for this grouping, or other
  message if one cannot be determined.
*/
// OPTIONAL (Idea 2a): Change parameter type to CapacityGroup
string GetCarpoolRecommendation(int group)
{
    string recommendation;

    switch( group )
    {
      case CG_9_12:  recommendation = "Dodge Sprinter Wagon";
                     break;
      case CG_7_8:   recommendation = "Ford E-150 XL";
                     break;
      case CG_5_6:   recommendation = "Chrysler Town and Country";
                     break;

      case CG_3_4:
      case CG_1_2:   recommendation = "Consider a smaller vehicle.";
                     break;

      default: recommendation = "No recommendation for this capacity.";
    }

    return recommendation;
}

//------------------------------------------------------------------------------

/*
  Gets a vehicle recommendation for FAMILY category based on the capacity grouping.

  POST CONDITION: return value is a vehicle recommended for this grouping, or other
  message if one cannot be determined.
*/
// OPTIONAL (Idea 2a): Change parameter type to CapacityGroup
string GetFamilyRecommendation(int group)
{
    string recommendation;

    switch( group )
    {
      case CG_9_12:  recommendation = "Consider a larger vehicle.";
                     break;

      case CG_7_8:   recommendation = "Honda Odyssey";
                     break;
      case CG_5_6:   recommendation = "Buick Lucerne";
                     break;
      case CG_3_4:   recommendation = "Chevy Malibu";
                     break;

      case CG_1_2:   recommendation = "Consider a smaller vehicle.";
                     break;

      default: recommendation = "No recommendation for this capacity.";
    }

    return recommendation;
}

//------------------------------------------------------------------------------

/*
  Gets a vehicle recommendation for SPORT category based on the capacity grouping.

  POST CONDITION: return value is a vehicle recommended for this grouping, or other
  message if one cannot be determined.
*/
// OPTIONAL (Idea 2a): Change parameter type to CapacityGroup
string GetSportRecommendation(int group)
{
    string recommendation;

    switch( group )
    {
      case CG_9_12:
      case CG_7_8:
      case CG_5_6:   recommendation = "Consider a larger vehicle.";
                     break;

      case CG_3_4:   recommendation = "Ford Mustang";
                     break;
      case CG_1_2:   recommendation = "Dodge Viper";
                     break;

      default: recommendation = "No recommendation for this capacity.";
    }

    return recommendation;
}

[Vladox]

What on earth...?

[kylet]

this is an assignment for an introduction to computer science class. Basically anything under "TO DO" or "Objective" can be assumed that I have done it wrong. I'm soo confused please help. I'm not looking for someone to write the code for me, as I really need to understand how to do it myself.