/*
C# A Beginner's Guide
By Schildt
Publisher: Osborne McGraw-Hill
ISBN: 0072133295
*/
/*
Project 9-1
Demonstrate the ICharQ interface.
*/
using System;
// A character queue interface.
public interface ICharQ {
// Put a characer into the queue.
void put(char ch);
// Get a character from the queue.
char get();
}
// A fixed-size queue class for characters.
class FixedQueue : ICharQ {
char[] q; // this array holds the queue
int putloc, getloc; // the put and get indices
// Construct an empty queue given its size.
public FixedQueue(int size) {
q = new char[size+1]; // allocate memory for queue
putloc = getloc = 0;
}
// Put a character into the queue.
public void put(char ch) {
if(putloc==q.Length-1) {
Console.WriteLine(” — Queue is full.”);
return;
}
putloc++;
q[putloc] = ch;
}
// Get a character from the queue.
public char get() {
if(getloc == putloc) {
Console.WriteLine(” — Queue is empty.”);
return (char) 0;
}
getloc++;
return q[getloc];
}
}
// A circular queue.
class CircularQueue : ICharQ {
char[] q; // this array holds the queue
int putloc, getloc; // the put and get indices
// Construct an empty queue given its size.
public CircularQueue(int size) {
q = new char[size+1]; // allocate memory for queue
putloc = getloc = 0;
}
// Put a character into the queue.
public void put(char ch) {
/* Queue is full if either putloc is one less than
getloc, or if putloc is at the end of the array
and getloc is at the beginning. */
if(putloc+1==getloc |
((putloc==q.Length-1) & (getloc==0))) {
Console.WriteLine(” — Queue is full.”);
return;
}
putloc++;
if(putloc==q.Length) putloc = 0; // loop back
q[putloc] = ch;
}
// Get a character from the queue.
public char get() {
if(getloc == putloc) {
Console.WriteLine(” — Queue is empty.”);
return (char) 0;
}
getloc++;
if(getloc==q.Length) getloc = 0; // loop back
return q[getloc];
}
}
// A dynamic queue.
class DynQueue : ICharQ {
char[] q; // this array holds the queue
int putloc, getloc; // the put and get indices
// Construct an empty queue given its size.
public DynQueue(int size) {
q = new char[size+1]; // allocate memory for queue
putloc = getloc = 0;
}
// Put a character into the queue.
public void put(char ch) {
if(putloc==q.Length-1) {
// increase queue size
char[] t = new char[q.Length * 2];
// copy elements into new queue
for(int i=0; i < q.Length; i++)
t[i] = q[i];
q = t;
}
putloc++;
q[putloc] = ch;
}
// Get a character from the queue.
public char get() {
if(getloc == putloc) {
Console.WriteLine(" -- Queue is empty.");
return (char) 0;
}
getloc++;
return q[getloc];
}
}
// Demonstrate the queues.
public class IQDemo {
public static void Main() {
FixedQueue q1 = new FixedQueue(10);
DynQueue q2 = new DynQueue(5);
CircularQueue q3 = new CircularQueue(10);
ICharQ iQ;
char ch;
int i;
iQ = q1;
// Put some characters into fixed queue.
for(i=0; i < 10; i++)
iQ.put((char) ('A' + i));
// Show the queue.
Console.Write("Contents of fixed queue: ");
for(i=0; i < 10; i++) {
ch = iQ.get();
Console.Write(ch);
}
Console.WriteLine();
iQ = q2;
// Put some characters into dynamic queue.
for(i=0; i < 10; i++)
iQ.put((char) ('Z' - i));
// Show the queue.
Console.Write("Contents of dynamic queue: ");
for(i=0; i < 10; i++) {
ch = iQ.get();
Console.Write(ch);
}
Console.WriteLine();
iQ = q3;
// Put some characters into circular queue.
for(i=0; i < 10; i++)
iQ.put((char) ('A' + i));
// Show the queue.
Console.Write("Contents of circular queue: ");
for(i=0; i < 10; i++) {
ch = iQ.get();
Console.Write(ch);
}
Console.WriteLine();
// Put more characters into circular queue.
for(i=10; i < 20; i++)
iQ.put((char) ('A' + i));
// Show the queue.
Console.Write("Contents of circular queue: ");
for(i=0; i < 10; i++) {
ch = iQ.get();
Console.Write(ch);
}
Console.WriteLine("
Store and consume from" +
" circular queue.");
// Use and consume from circular queue.
for(i=0; i < 20; i++) {
iQ.put((char) ('A' + i));
ch = iQ.get();
Console.Write(ch);
}
}
}
[/csharp]