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Queue Using LL.cpp
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Queue Using LL.cpp
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#include <iostream>
using namespace std;
int size=5; //Size will be compared in every function so defining it globally
struct node{ //will be used as node of a linked list
int data;
node *next;
};
void push(node** head){
int c=0; //c will count no. of element in stack
node *temp=*head,*pre;
while(temp!=0)
{
pre=temp;
temp=temp->next;
c++;
} //c will have count of number of element,and pre will point to last element node
if(c==size) //if nodes==size i.e queue is full
cout<<"\n\t!!! Queue OVERFLOW !!!";
else //adding nodes from end
{
node *newnode=new node();
cout<<"\nEnter data ";cin>>newnode->data;
newnode->next=0;
if(*head==0) //if its first element to be added then it will be pointed by head
*head=newnode;
else
pre->next=newnode; //last element will point to newnode and newnode will be end element
cout<<"\n"<<newnode->data <<" is added to Queue";
}
}
void pop(node** head){
int c=0;
node *temp=*head;
if(*head==0) //if queue is empty
cout<<"\n\t!!! Queue UNDERFLOW !!!";
else //deleting element from head side
{
cout<<"\n"<<(*head)->data<<" DELETED ";
*head=(*head)->next;
delete temp;
}
}
void peek(node** head){ //prints element @ the end i.e element which was added first
int c=1;
node *temp=*head;
while(temp->next!=0)
{
temp=temp->next;
c++;
}
if(c==1)
cout<<"\n\t!!! Queue UNDERFLOW !!!";
else
cout<<"\nTop Element : "<<(*head)->data;
}
void display(node** head){
int c=1;
node *temp=*head;
while(temp->next!=0)
{
temp=temp->next;
c++;
}
if(c==1)
cout<<"\n\t!!! Queue UNDERFLOW !!!";
else
{
node *t=*head;
cout<<"\nQUEUE IS : ";
while(t!=0)
{
cout<<"\n"<<t->data;
t=t->next;
}
}
}
int main(){
node *head=0;
int choice;
do{
cout<<"\n~~~ MENU ~~~\n1.PUSH\t2.POP\t3.Peek\t4.Display\t5.Exit\n ";
cin>>choice;
switch(choice)
{
case 1:push(&head);break;
case 2:pop(&head);break;
case 3:peek(&head);break;
case 4:display(&head);break;
case 5:cout<<"\n~~~ THANK YOU ~~~";break;
default:cout<<"\nInvalid choic try again ";
}
}while(choice!=5);
}