StackImpl.groovy

public class StackImpl {

    private int[] ele

    private int MAX_SIZE

    private int top = -1

    int size(){
        top
    }

    StackImpl(int size) {
        MAX_SIZE = size
        ele = new int[MAX_SIZE]
    }

    int peek() {
        if(top < 0)
            throw new Exception("Stack is Empty")
        ele[top]
    }

    void push(int e) {
        if(size() == MAX_SIZE)
            throw new Exception("StackOverflow")
        ele[top++] = e
        println "Element added in top of stack"
        println ele
    }

    int pop() {
        int element
        if(top < 0)
            throw new Exception("Stack is Empty, Can't read")
        element = ele[top]
        ele[top] = Integer.MIN_VALUE
        top--
        return element
    }
}