#include using namespace std; class node { public: int data; //data node *next; //pointer node(int x) { data = x; next = NULL; } }; class Queue { public: node *front;//v10,nNull// node *back;//v10,nNull// //O(1) Amazing void enqueue(node *n) { if(back == NULL) { //front and back are pointing to //the same node's memory address cout<<"if"<next = n;//20 //then assign the node to the //back. back = n;//20 //this works because first has //the first Node saved,so when //back->Next is assigned it is //also assigned to the first. //so back can be changed //without loosing data.:D } } void dequeue() { if(front == NULL) return; node* n = front; front = front->next; if(front == NULL) back = NULL; delete(n); } void print() { node* ptr = front; while(ptr != NULL) { cout <<"("<data<<" :"; cout << &ptr->data<<")->"; ptr = ptr->next; } } Queue() { front = back = NULL; } }; int main() { Queue Q; node *n1 = new node(7); node *n2 = new node(78); node *n3 = new node(11); Q.enqueue(n1); Q.enqueue(n2); Q.enqueue(n3); Q.print(); cout << endl; Q.dequeue(); Q.print(); delete [] n1; delete [] n2; delete [] n3; return 0; }

Queue.cpp