Queue Implemented by a Linked List

Queue:是一種先進先出的資料結構(First In First Out).
下面的範例程式使用C++ 的Linked List來實現Queue.

#include <iostream>
using namespace std;

class Node {

public:
 int data;
 Node* nxtNode;
 Node(int _data) {
  data=_data;//Data
  nxtNode=NULL;//pointer to next one
 }
};

class LinkedList {
 Node* previous;
 Node* next;
public:
 LinkedList() {
  previous=NULL;
  next=NULL;
 }

 void insert(Node * _node) {
  if (previous==NULL) {
   previous= next= _node;//first node
  } else {
   (*next).nxtNode=_node;
   next=_node;
  }
 }

 void displayAll() {
  Node* tmp=previous;
  while(tmp!=NULL){
   cout<<(*tmp).data <<endl;
   tmp=(*tmp).nxtNode;
  }
 }
};

int main() {
 Node* firstNode=new Node(1);
 Node* secondNode=new Node(2);
 Node* thirdNode=new Node(3);
 LinkedList ll;
 ll.insert(firstNode);
 ll.insert(secondNode);
 ll.insert(thirdNode);
 ll.displayAll();
 return 0;
}