ResilientSpring · ResilientSpring · Oct 3, 2023 · Oct 3, 2023 · Oct 3, 2023 · Oct 3, 2023
diff --git a/Chapter8/Try_This_8_1.java b/Chapter8/Try_This_8_1.java
@@ -0,0 +1,201 @@
+// A character queue interface
+
+interface ICharQ{
+
+	// Put a character into the queue.
+	void put(char ch);
+
+	// Get a character from the queue.
+	char get();
+}
+
+
+// A fixed-size queue class for characters.
+class FixedQueue implements ICharQ{
+
+	private char q[];  // This array holds the queue. 
+	private int putloc, getloc; // The put and get indices.
+
+	public FixedQueue(int size) {
+		q = new char[size];  // allocate memory for queue.
+		putloc = getloc = 0;
+	}
+
+	public void put(char ch) {
+		if(putloc == q.length) {
+			System.out.println(" - Queue is full.");
+			return;
+		}
+
+		q[putloc++] = ch;
+	}
+
+	public char get() {
+
+		if (getloc == putloc) {
+			System.out.println(" - Queue is empty.");
+
+			return (char) 0;
+		}
+		return q[getloc++];
+	}
+
+}
+
+class CircularQueue implements ICharQ{
+	private char q[];  // this array holds the queue.
+	private 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;
+	}
+
+	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))) {
+			System.out.println(" - Queue is full. ");
+			return;
+		}
+
+		q[putloc++] = ch;
+
+		if (putloc == q.length) {
+			putloc = 0;
+		}
+
+	}
+
+	public char get() {
+		// TODO Auto-generated method stub
+		if (getloc == putloc) {
+			System.out.println(" - Queue is empty.");
+			return (char) 0;
+		}
+
+		char ch = q[getloc++];
+
+		if (getloc == q.length) {
+			getloc = 0;
+		}
+
+		return ch;
+	}
+}
+
+
+class DynQueue implements ICharQ{
+
+	private char q[];
+	private int putloc, getloc;
+
+	public DynQueue(int size) {
+		q = new char[size];
+		putloc = getloc = 0;
+	}
+
+
+	public void put(char ch) {
+		// TODO Auto-generated method stub
+
+		if (putloc == q.length) {
+			// 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;
+			}
+			q[putloc++] = ch;
+		}
+
+	}
+
+
+	public char get() {
+
+		if (getloc == putloc) {
+			System.out.println(" - Queue is empty.");
+			return (char) 0;
+		} 
+
+		return q[getloc++];
+
+	}
+
+}
+
+
+public class Try_This_8_1 {
+
+	public static void main(String[] args) {
+		// TODO Auto-generated method stub
+
+		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.
+		System.out.print("Contents of fixed queue: ");
+
+		for (i = 0; i < 10; i++) {
+			ch = iQ.get();
+			System.out.print(ch);
+		}
+
+		System.out.println();
+
+		iQ = q2;
+
+		// Put some characters into dynamic queue.
+		for (i = 0; i < 10; i++) {
+			iQ.put((char) ('Z' - i));
+		}
+
+		// Show the queue.
+		System.out.print("Contents of dynamic queue: ");
+		for (i = 0; i < 10; i++) {
+			ch = iQ.get();
+			System.out.print(ch);
+		}
+
+
+		System.out.println();
+
+		iQ = q3;
+
+		// Put some characters into circular queue.
+		for (i = 0; i < 20; i++) {
+			iQ.put((char) ('A' + i));
+		}
+
+		// Show the queue.
+		System.out.print("Contents of circular queue: ");
+		for (i = 0; i < 10; i++) {
+
+		}
+
+	}
+
+}