数据结构之栈

数据结构

特性

• 先进后出 FILO (First in last out)
• 栈顶进，栈顶出
• 两种实现
  
  • 基于动态数组
  • 基于链表

接口列表

• void push(E e)
• E pop()
• E peek()
• int getSize()
• boolean isEmpty()

示例代码

• 接口定义

public interface Stack<E> {
    public int getSize();
    public boolean isEmpty();
    public void push(E e);
    public E pop();
    public E peek();
}

• 1、基于动态数组的实现

public class ArrayStack<E> implements Stack<E> {
    Array<E> array;
    public ArrayStack(int capacity) {
        this.array = new Array<>(capacity);
    }
    public ArrayStack() {
        this.array = new Array<>();
    }
    @Override
    public int getSize() {
        return this.array.getSize();
    }
    @Override
    public boolean isEmpty() {
        return this.array.isEmpty();
    }
    public int getCapacity() {
        return this.array.getCapacity();
    }
    @Override
    public void push(E e) {
        this.array.addLast(e);
    }
    @Override
    public E pop() {
        return this.array.removeLast();
    }
    @Override
    public E peek() {
        return this.array.getLast();
    }
    @Override
    public String toString() {
        StringBuilder res = new StringBuilder();
        res.append("Stack: ");
        res.append('[');
        for (int i = 0; i < this.array.getSize(); i++) {
            res.append(array.get(i));
            if (i != this.array.getSize() - 1) {
                res.append(", ");
            }
        }
        res.append("] top");
        return res.toString();
    }
}