Stack is used to store particular type of data. Stack is a memory area where we can store all local variables and parameters used in our functions.

In Stack we can perform three operations that are :

Push - to add something in stack with complexity of O(1)

Pop -  to delete something from stack with complexity of O(1)

Search -  traverse all items of stack with complexity of O(n)

Array based implementation of stack is easy and efficient :

public class StackOperations  {

    private int top;
    private int storage;
    private int stack[];

    public StackOperations(int n, int storage){
        this.top = n;
        this.storage = storage;
        stack = new int[storage];
    }

    public void push(int value){

        top++;

        if (top == -1){
            Log.e(" stack empty"," stack empty");
        }else if (top == storage){
            Log.e(" stack overflow"," stack overflow");
            top--;
        }else{
            stack[top] = value;
        }

    }

    public void pop(){

        if (top == -1){
            Log.e(" stack empty"," stack empty");
        }

            top--;

    }

    public void peek(){

        if (top == -1){
            Log.e(" stack empty"," stack empty");
        }else{
            for (int i =0 ; i<=top;i++){
                Log.e(" stack data"," :: " + stack[i]);
            }
        }
    }


}