Java 实现Stack数据结构-学习记录

package stack;

/**
 * @Title: Stack
 * @ProjectName Demo03
 * @date 2018/9/12
 */
public interface Stack<E> {
    int getSize();
    boolean isEmpty();
    void push(E e);
    E pop();
    E peek();
}

　　

package stack;

import array.Array;

/**
 * @Title: ArrayStack
 * @ProjectName Demo03
 * @date 2018/9/12
 */
public class ArrayStack<E> implements Stack<E> {
    private Array<E> array;
    public ArrayStack() {
        array = new Array<>();
    }

    public ArrayStack(int capacity) {
        array = new Array<>(capacity);
    }
    @Override
    public int getSize() {
        return array.getSize();
    }

    @Override
    public boolean isEmpty() {
        return array.isEmpty();
    }

    @Override
    public void push(E e) {
        array.addLast(e);
    }

    @Override
    public E pop() {
        return array.removeLast();
    }

    @Override
    public E peek() {
        return array.getLast();
    }

    @Override
    public String toString() {
        StringBuilder res = new StringBuilder();
        res.append("Stack: [");
        for (int i = 0; i < array.getSize(); i++) {
            res.append(array.get(i));
            if (i != array.getSize() - 1) {
                res.append(",");
            }
        }
        res.append("] top");
        return res.toString();
    }

    public static void main(String[] args) {
        ArrayStack<String> arrayStack = new ArrayStack<>();
        arrayStack.push("a");
        arrayStack.push("b");
        arrayStack.push("c");
        System.out.println(arrayStack);
        String pop = arrayStack.pop();
        System.out.println(pop);
        System.out.println(arrayStack);
        System.out.println(arrayStack.peek());
    }
}