stacks.java

public class Stack {
	int top;
	int[] stackA;
	int size;
	
	public Stack(int size){
		stackA = new int[size];
		top = -1;
		this.size=size;
				
	}
	public void push(int data){
		if(top+1<this.size){
			top++;
			stackA[top]=data;
		}
		else{
			System.out.println("stack is full");
		}
		
	}
	public void pop(){
		
		if(size()>0){
			System.out.println(stackA[top]);
			stackA[top] =-1;
			top--;
		}
		else{
			System.out.println("empty stack");
		}
		
	}
	public int size(){
		return top+1;
	}
	public void peek(){
		System.out.println(stackA[top]);
	}
	
	public static void main(String []args){
		Stack stack = new Stack(10);
		stack.push(1);
		stack.push(2);
		stack.push(3);
		stack.push(4);
		stack.push(5);
		stack.push(6);
		stack.push(7);
		stack.push(8);
		stack.push(9);
		stack.push(10);
		stack.push(11);
		System.out.println(stack.size());
		stack.peek();
	}

}

what will be your approach if we need a dynamically growing stack.....

In place of fixed array can we use other ds....in c++ vector is a solution bcoz vector grow dynamic but lot of allocation deallocation so i prefer a singly linklist

insert method do insert at begining and top will be head

Insert 2 3 4 5 6 7
Top
|
7-->6--->5---->3----->2