Stack Operation

 

Stack:Push,Pop, is empty

A stack is an Abstract Data Type (ADT), commonly used in most programming languages. It is named stack as it behaves like a real-world stack, for example – a deck of cards or a pile of plates, etc. A real-world stack allows operations at one end only. For example, we can place or remove a card or plate from the top of the stack only.

Basic Operations:

Stack operations may involve initializing the stack, using it and then de-initializing it.   Apartfrom these basic stuffs, a stack is used for the following two primary operations −

Ø  push ()− Pushing (storing) an element on the stack.

Ø  pop ()− Removing (accessing) an element from the stack.

 

To use a stack efficiently, we need to check the status of stack as well. For the same purpose, the following functionality is added to stacks −

Ø    Peek () − get the top data element of the stack, without removing it.

Ø    isFull () − check if stack is full.

Ø    isEmpty () − check if stack is empty

 

Code#1:

#include <iostream>

using namespace std;

int stack[100], n=100, top=-1;

void push(int val) {

   if(top>=n-1)

   cout<<"Stack Overflow"<<endl;

   else {

      top++;

      stack[top]=val;

   }

}

void pop() {

   if(top<=-1)

   cout<<"Stack Underflow"<<endl;

   else {

      cout<<"The popped element is "<< stack[top] <<endl;

      top--;

   }

}

void display() {

   if(top>=0) {

      cout<<"Stack elements are:";

      for(int i=top; i>=0; i--)

      cout<<stack[i]<<" ";

      cout<<endl;

   } else

   cout<<"Stack is empty";

}

int main() {

   int ch, val;

   cout<<"1) Push in stack"<<endl;

   cout<<"2) Pop from stack"<<endl;

   cout<<"3) Display stack"<<endl;

   cout<<"4) Exit"<<endl;

   do {

      cout<<"Enter choice: "<<endl;

      cin>>ch;

      switch(ch) {

         case 1: {

            cout<<"Enter value to be pushed:"<<endl;

            cin>>val;

            push(val);

            break;

         }

         case 2: {

            pop();

            break;

         }

         case 3: {

            display();

            break;

         }

         case 4: {

            cout<<"Exit"<<endl;

            break;

         }

         default: {

            cout<<"Invalid Choice"<<endl;

         }

      }

   }while(ch!=4);

   return 0;

}