C++ Programming Code Examples
C++ > Data Structures and Algorithm Analysis in C++ Code Examples
Implementation for linked list
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/* Implementation for linked list */
#include "LinkedList.h"
/**
* Construct the list
*/
template <class Object>
List<Object>::List( )
{
header = new ListNode<Object>;
}
/**
* Copy constructor
*/
template <class Object>
List<Object>::List( const List<Object> & rhs )
{
header = new ListNode<Object>;
*this = rhs;
}
/**
* Destructor
*/
template <class Object>
List<Object>::~List( )
{
makeEmpty( );
delete header;
}
/**
* Test if the list is logically empty.
* return true if empty, false otherwise.
*/
template <class Object>
bool List<Object>::isEmpty( ) const
{
return header->next == NULL;
}
/**
* Make the list logically empty.
*/
template <class Object>
void List<Object>::makeEmpty( )
{
while( !isEmpty( ) )
remove( first( ).retrieve( ) );
}
/**
* Return an iterator representing the header node.
*/
template <class Object>
ListItr<Object> List<Object>::zeroth( ) const
{
return ListItr<Object>( header );
}
/**
* Return an iterator representing the first node in the list.
* This operation is valid for empty lists.
*/
template <class Object>
ListItr<Object> List<Object>::first( ) const
{
return ListItr<Object>( header->next );
}
/**
* Insert item x after p.
*/
template <class Object>
void List<Object>::insert( const Object & x, const ListItr<Object> & p )
{
if( p.current != NULL )
p.current->next = new ListNode<Object>( x, p.current->next );
}
/**
* Return iterator corresponding to the first node containing an item x.
* Iterator isPastEnd if item is not found.
*/
template <class Object>
ListItr<Object> List<Object>::find( const Object & x ) const
{
/* 1*/ ListNode<Object> *itr = header->next;
/* 2*/ while( itr != NULL && itr->element != x )
/* 3*/ itr = itr->next;
/* 4*/ return ListItr<Object>( itr );
}
/**
* Return iterator prior to the first node containing an item x.
*/
template <class Object>
ListItr<Object> List<Object>::findPrevious( const Object & x ) const
{
/* 1*/ ListNode<Object> *itr = header;
/* 2*/ while( itr->next != NULL && itr->next->element != x )
/* 3*/ itr = itr->next;
/* 4*/ return ListItr<Object>( itr );
}
/**
* Remove the first occurrence of an item x.
*/
template <class Object>
void List<Object>::remove( const Object & x )
{
ListItr<Object> p = findPrevious( x );
if( p.current->next != NULL )
{
ListNode<Object> *oldNode = p.current->next;
p.current->next = p.current->next->next; // Bypass deleted node
delete oldNode;
}
}
/**
* Deep copy of linked lists.
*/
template <class Object>
const List<Object> & List<Object>::operator=( const List<Object> & rhs )
{
ListItr<Object> ritr = rhs.first( );
ListItr<Object> itr = zeroth( );
if( this != &rhs )
{
makeEmpty( );
for( ; !ritr.isPastEnd( ); ritr.advance( ), itr.advance( ) )
insert( ritr.retrieve( ), itr );
}
return *this;
}
In C++, classes and structs are blueprints that are used to create the instance of a class. Structs are used for lightweight objects such as Rectangle, color, Point, etc. Unlike class, structs in C++ are value type than reference type. It is useful if you have data that is not intended to be modified after creation of struct. C++ Structure is a collection of different data types. It is similar to the class that holds different types of data. A structure is declared by preceding the struct keyword followed by the identifier(structure name). Inside the curly braces, we can declare the member variables of different types.
The pointer in C++ language is a variable, it is also known as locator or indicator that points to an address of a value. In C++, a pointer refers to a variable that holds the address of another variable. Like regular variables, pointers have a data type. For example, a pointer of type integer can hold the address of a variable of type integer. A pointer of character type can hold the address of a variable of character type. You should see a pointer as a symbolic representation of a memory address. With pointers, programs can simulate call-by-reference. They can also create and manipulate dynamic data structures. In C++, a pointer variable refers to a variable pointing to a specific address in a memory pointed by another variable.
Templates are powerful features of C++ which allows us to write generic programs. Similar to function templates, we can use class templates to create a single class to work with different data types. Class templates come in handy as they can make our code shorter and more manageable. A class template starts with the keyword template followed by template parameter(s) inside <> which is followed by the class declaration. T is the template argument which is a placeholder for the data type used, and class is a keyword. Inside the class body, a member variable var and a member function functionName() are both of type T.
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Every object in C++ has access to its own address through an important pointer called this pointer. The this pointer is an implicit parameter to all member functions. Therefore, inside a member function, this may be used to refer to the invoking object. Friend functions do not have a this pointer, because friends are not members of a class. Only member functions have a this pointer. In C++ programming, this is a keyword that refers to the current instance of the class. There can be 3 main usage of this keyword in C++: • It can be used to pass current object as a parameter to another method. • It can be used to refer current class instance variable. • It can be used to declare indexers. To understand 'this' pointer, it is important to know how objects look at functions and data members of a class.
A C++ template is a powerful feature added to C++. It allows you to define the generic classes and generic functions and thus provides support for generic programming. Generic programming is a technique where generic types are used as parameters in algorithms so that they can work for a variety of data types. We can define a template for a function. For example, if we have an add() function, we can create versions of the add function for adding the int, float or double type values. Where Ttype: It is a placeholder name for a data type used by the function. It is used within the function definition. It is only a placeholder that the compiler will automatically replace this placeholder with the actual data type. class: A class keyword is used to specify a generic type in a template declaration.
Advance iterator. Advances the iterator it by n element positions. If it is a random-access iterator, the function uses just once operator+ or operator-. Otherwise, the function uses repeatedly the increase or decrease operator (operator++ or operator--) until n elements have been advanced. This function does not return any value.
In computer programming, we use the if statement to run a block code only when a certain condition is met. An if statement can be followed by an optional else statement, which executes when the boolean expression is false. There are three forms of if...else statements in C++: • if statement, • if...else statement, • if...else if...else statement, The if statement evaluates the condition inside the parentheses ( ). If the condition evaluates to true, the code inside the body of if is executed. If the condition evaluates to false, the code inside the body of if is skipped.
Logical Operators are used to compare and connect two or more expressions or variables, such that the value of the expression is completely dependent on the original expression or value or variable. We use logical operators to check whether an expression is true or false. If the expression is true, it returns 1 whereas if the expression is false, it returns 0. Assume variable A holds 1 and variable B holds 0:
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In computer programming, loops are used to repeat a block of code. For example, when you are displaying number from 1 to 100 you may want set the value of a variable to 1 and display it 100 times, increasing its value by 1 on each loop iteration. When you know exactly how many times you want to loop through a block of code, use the for loop instead of a while loop. A for loop is a repetition control structure that allows you to efficiently write a loop that needs to execute a specific number of times.
Deallocate storage space. Default deallocation functions (single-object form). A delete operator is used to deallocate memory space that is dynamically created using the new operator, calloc and malloc() function, etc., at the run time of a program in C++ language. In other words, a delete operator is used to release array and non-array (pointer) objects from the heap, which the new operator dynamically allocates to put variables on heap memory. We can use either the delete operator or delete [ ] operator in our program to delete the deallocated space. A delete operator has a void return type, and hence, it does not return a value.
#include is a way of including a standard or user-defined file in the program and is mostly written at the beginning of any C/C++ program. This directive is read by the preprocessor and orders it to insert the content of a user-defined or system header file into the following program. These files are mainly imported from an outside source into the current program. The process of importing such files that might be system-defined or user-defined is known as File Inclusion. This type of preprocessor directive tells the compiler to include a file in the source code program.
To find 'cube root of any number' we need to find 0.3 power of any number. if you need to find cube root of 27 then calculate 0.3 power of 27, result is 3. So another method for this
