using System;
public class Node {
public Node next;
public string value;
public Node(string value) {
this.value = value;
}
}
class Queue {
Node first;
Node last;
int length = 0;
static void Main() {
Console.WriteLine("Hello World!");
Queue q = new Queue();
Console.WriteLine("q: " + q.ToString());
q.Enqueue("a");
Console.WriteLine("q: " + q.ToString());
q.Enqueue("b");
Console.WriteLine("q: " + q.ToString());
q.Enqueue("c");
Console.WriteLine("q: " + q.ToString());
q.Dequeue();
Console.WriteLine("q: " + q.ToString());
q.Dequeue();
Console.WriteLine("q: " + q.ToString());
q.Dequeue();
Console.WriteLine("q: " + q.ToString());
}
public void Enqueue(string value) {
Node item = new Node(value);
if (this.length == 0) {
this.first = item;
} else {
this.last.next = item;
}
this.last = item;
this.length++;
}
public string Dequeue() {
if (this.first != null) {
string value = this.first.value;
this.first = this.first.next;
this.length--;
return value;
}
return null;
}
public string Peek() {
if (this.first != null) {
return this.first.value;
}
return null;
}
public bool IsEmpty() {
return this.length == 0;
}
public string ToString() {
string s = "{";
Node current = this.first;
int count = 0;
while (current != null) {
if (count > 0) {
s += ", ";
}
s += "" + current.value;
current = current.next;
count++;
}
s += "}";
return s;
}
}
