gistfile1.java

/**
 *
 * @author Pedro
 */
public class Stack {
    
    private Node top;
    private int nElems;
    
    public Stack() {
        top = null;
        nElems = 0;
    }
    
    public void push(char c) {
        Node n = new Node(c);
        n.setBellowNode(top);
        top = n;
        nElems++;
    }
    
    public void pop() {
        top = top.getBellowNode();
        nElems--;
    }
    
    public void popN(int n) {
        while(n != 0 || top != null) {
            pop();
            n--;
        }
    }
    
    public void print() {
        Node tmp = top;
        while(tmp != null) {
            System.out.print("->" + tmp.getChar());
            tmp = tmp.getBellowNode();
        }
    }
    
    private class Node {
        
        private Node bellow;
        private char c;
        
        public Node(char c) {
            this.c = c;
            bellow = null;
        }
        
        public void setBellowNode(Node n) {
            this.bellow = n;
        }
        
        public Node getBellowNode() {
            return bellow;
        }
        
        public char getChar() {
            return c;
        }
    }
}