implement the Stack ADT,Queue ADT using an array.

stack ADT
import java.io.*;
class stackclass
{
int top,ele,stack[],size;
stackclass(int n)
{
stack=new int[n];
size=n;
top=-1;
}
void push(int x)
{
ele=x;
stack[++top]=ele;
}
int pop()
{
if(!isempty())
{
System.out.println("Deleted element is");
return stack[top--];
}
else
{
System.out.println("stack is empty");
return -1;
}
}
boolean isempty()
{
if(top==-1)
return true;
else
return false;
}
boolean isfull()
{
if(size>(top+1))
return false;
else
return true;
}
int peek()
{
if(!isempty())
return stack[top];
else
{
System.out.println("stack is empty");
return -1;
}
}
void size()
{
System.out.println("size of the stack is :"+(top+1));
}
void display()
{
if(!isempty())
{
for(int i=top;i>=0;i--)
System.out.print(stack[i]+" ");
}
else
System.out.println("stack is empty");
}
}class stacktest
{
public static void main(String args[])throws Exception
{
BufferedReader br=new BufferedReader(new InputStreamReader(System.in));
System.out.println("enter the size of stack");
int size=Integer.parseInt(br.readLine());
stackclass s=new stackclass(size);
int ch,ele;
do
{
System.out.println();
System.out.println("1.push");
System.out.println("2.pop");
System.out.println("3.peek");
System.out.println("4.size");
System.out.println("5.display");
System.out.println("6.is empty");
System.out.println("7.is full");
System.out.println("8.exit");
System.out.println("enter ur choise :");
ch=Integer.parseInt(br.readLine());
switch(ch)
{
case 1:if(!s.isfull())
{
System.out.println("enter the element to insert: ");
ele=Integer.parseInt(br.readLine());
s.push(ele);
}
else
{
System.out.print("stack is overflow");
}
break;
case 2:int del=s.pop();
if(del!=-1)
System.out.println(del+" is deleted");
break;
case 3:int p=s.peek();
if(p!=-1)
System.out.println("peek element is: "+p);
break;
case 4:s.size();
break;
case 5:s.display();
break;
case 6:boolean b=s.isempty();
System.out.println(b);
break;
case 7:boolean b1=s.isfull();
System.out.println(b1);
break;
}
}
while(ch!=0);
}
}

queue ADT
import java.util.*;
class queue
{
int front,rear;
int que[];
int max,count=0;
queue(int n)
{
max=n;
que=new int[max];
front=rear=-1;
}
boolean isfull()
{
if(rear==(max-1))
return true;
else
return false;
}
boolean isempty()
{
if(front==-1)
return true;
else
return false;
}
void insert(int n)
{
if(isfull())
System.out.println("list is full");
else
{
rear++;
que[rear]=n;
if(front==-1)
front=0;
count++;
}
}
int delete()
{
int x;
if(isempty())
return -1;
else
{
x=que[front];
que[front]=0;
if(front==rear)
front=rear=-1;
else
front++;
count--;
}
return x;
}
void display()
{
if(isempty())
System.out.println("queue is empty");
else
for(int i=front;i<=rear;i++)
System.out.println(que[i]);
}
int size()
{
return count;
}
public static void main(String args[])
{
int ch;
Scanner s=new Scanner(System.in);
System.out.println("enter limit");
int n=s.nextInt();
queue q=new queue(n);
do
{
System.out.println("1.insert");
System.out.println("2.delete");
System.out.println("3.display");
System.out.println("4.size");
System.out.println("enter ur choise :");
ch=s.nextInt();
switch(ch)
{
case 1:System.out.println("enter element :");
int n1=s.nextInt();
q.insert(n1);
break;
case 2:int c1=q.delete();
if(c1>0)
System.out.println("deleted element is :"+c1);
else
System.out.println("can't delete");
break;
case 3:q.display();
break;
case 4:System.out.println("queue size is "+q.size());
break;
}
}
while(ch!=0);
}
}