WordPile is an entity which can hold maximum of 20 characters. The restriction is that a character can be added or removed from one end only.
Some of the members of classes are given below:
Class name : WordPile
Data members/instance variables:
ch[ ] : character array to hold the character elements
capacity : integer variable to store the maximum capacity
top : to point to the index of the topmost element
Methods/Member functions:
WordPile( int cap) : constructor to initialise the data member capacity = cap, top = -1 and create the WordPile
void pushChar( char v) : adds the character to the top of WordPile if possible, otherwise output a message “WordPile is full”
char popChar() : returns the deleted character from the top of the
WordPile if possible, otherwise it returns ‘\\’
(a) Specify the class WordPile giving the details of the constructor, voidpushChar(char) and char opChar(). The main function and algorithm need not be written.
(b) What is the name of the entity described above and state one of its applications.
public class WordPile
{
char ch[] = new char[20];
int capacity,top;
WordPile(int cap)
{
capacity=cap;
top=-1;
ch=new char[capacity];
}
void pushChar(char v)
{
if(top<capacity-1)
ch[++top]=v;
else
System.out.println("WordPile is full");
}
char popChar()
{
if(top>=0)
return ch[top--];
else
return '\\';
}
}
(b)
Name of the Entity : Stack. Application : LIFO (Last In First Out ) , Recursion , Undo, infix to postfix
