stack

class Stack
{
    private int maxSize;
    private char[] stackArray;
    private int top;
    public Stack(int s)
    {
        maxSize = s;
        stackArray = new char[maxSize];
        top = -1;
    }
    public void push(char j)
    { stackArray[++top] = j; }
    public char pop()
    { return stackArray[top--]; }
    public char peek()
    { return stackArray[top]; }
    public boolean isEmpty()
    { return (top == -1); }
    public int size()
    { return top+1; }
    public char peekN(int n)
    { return stackArray[n]; }
}