/*
Classes and objects
Stack data structures
*/
import java.io.*;
import java.util.*;
class StkDS
{
int tos, capacity;
int [] Stk;
public StkDS(int c)
{
tos = -1;
capacity = c;
Stk = new int[capacity];
}
int size()
{
return tos+1;
}
boolean isFull()
{
return((tos+1) == capacity);
}
boolean isEmpty()
{
return (tos==-1);
}
void push(int x)
{
if(!isFull())
Stk[++tos]=x;
else
System.out.print("\nFull stack. Cant insert element.");
}
void pop()
{
if(!isEmpty())
tos--;
else
System.out.print("\nEmpty stack. Cant delete element.");
}
int topandpop()
{
if(!isEmpty())
return(Stk[tos--]);
else
{
System.out.print("\nEmpty stack. Cant delete element.");
return -1;
}
}
void peek()
{
if(!isEmpty())
System.out.print("\nElement on top of stack is "+Stk[tos]);
else
System.out.print("\nEmpty stack. No element present.");
}
void fnDisplay()
{
if(!isEmpty())
{
System.out.print("\nElements in stack : ");
for(int i=0;i<=tos;i++)
System.out.print(Stk[i]+" ");
}
else
System.out.println("\nEmpty stack. No elements present. ");
}
}
class StackDS
{
public static void main(String []as)throws IOException
{
Scanner sc = new Scanner(System.in);
System.out.print("\nEnter stack size : ");
int cap = sc.nextInt();
StkDS s = new StkDS(cap);
int choice;
do
{
System.out.print("\nMenu: 1. Push\t2. Pop\t3. TopandPop\t4. Peek\t5. Exit");
System.out.print("\nEnter choice : ");
choice = sc.nextInt();
switch(choice)
{
case 1: System.out.print("\nEnter element : ");
int ele=sc.nextInt();
s.push(ele);
s.fnDisplay();break;
case 2: s.pop();s.fnDisplay();break;
case 3: int val=s.topandpop();
System.out.println("\nDeleted element : "+val);
s.fnDisplay();break;
case 4: s.peek();s.fnDisplay();break;
case 5: System.exit(0);
}
}while(true);
}
}
