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// FILE: bag3.h
// CLASS PROVIDED: bag (part of the namespace main_savitch_5)
//
// TYPEDEFS for the bag class:
// bag::value_type
// is the data type of the items in the bag. It may be any
// of the C++ built-in types (int, char, etc.), or a class with a default
// constructor, a copy constructor, an assignment
// operator, and a test for equality (x == y).
//
// bag::size_type
// is the data type of any variable that keeps track of how many items are
// in a bag
//
// CONSTRUCTOR for the bag class:
// bag( )
// Postcondition: The bag is empty.
//
// MODIFICATION MEMBER FUNCTIONS for the bag class:
// size_type erase(const value_type& target)
// Postcondition: All copies of target have been removed from the bag.
// The return value is the number of copies removed (which could be zero).
//
// bool erase_one(const value_type& target)
// Postcondition: If target was in the bag, then one copy of target has
// been removed from the bag; otherwise the bag is unchanged. A true
// return value indicates that one copy was removed; false indicates that
// nothing was removed.
//
// void insert(const value_type& entry)
// Postcondition: A new copy of entry has been inserted into the bag.
//
// void operator +=(const bag& addend)
// Postcondition: Each item in addend has been added to this bag.
//
// CONSTANT MEMBER FUNCTIONS for the bag class:
// size_type size( ) const
// Postcondition: Return value is the total number of items in the bag.
//
// size_type count(const value_type& target) const
// Postcondition: Return value is number of times target is in the bag.
//
// value_type grab( ) const
// Precondition: size( ) > 0.
// Postcondition: The return value is a randomly selected item from the bag.
//
// NONMEMBER FUNCTIONS for the bag class:
// bag operator +(const bag& b1, const bag& b2)
// Postcondition: The bag returned is the union of b1 and b2.
//
// VALUE SEMANTICS for the bag class:
// Assignments and the copy constructor may be used with bag objects.
//
// DYNAMIC MEMORY USAGE by the bag:
// If there is insufficient dynamic memory, then the following functions throw
// bad_alloc: The constructors, insert, operator +=, operator +, and the
// assignment operator.
#ifndef MAIN_SAVITCH_BAG3_H
#define MAIN_SAVITCH_BAG3_H
#include <cstdlib> // Provides size_t and NULL
#include "node1.h" // Provides node class
namespace main_savitch_5
{
class bag
{
public:
// TYPEDEFS
typedef std::size_t size_type;
typedef node::value_type value_type;
// CONSTRUCTORS and DESTRUCTOR
bag( ); // bag b2;
bag(const bag& source); // bag b3(b2);
~bag( );
// MODIFICATION MEMBER FUNCTIONS
size_type erase(const value_type& target);
bool erase_one(const value_type& target);
void insert(const value_type& entry);
void operator +=(const bag& addend);
void operator =(const bag& source);
// CONSTANT MEMBER FUNCTIONS
size_type size( ) const { return many_nodes; }
size_type count(const value_type& target) const;
value_type grab( ) const;
private:
node *head_ptr; // List head pointer
size_type many_nodes; // Number of nodes on the list
};
// NONMEMBER FUNCTIONS for the bag class:
bag operator +(const bag& b1, const bag& b2);
}
#endif
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