Java使用链表模拟栈

使用头结点记录栈顶位置，采取头插法入栈，出栈时删除头结点的Next节点即可

package 栈;

public class LinkListStackDemo {
    public static void main(String[] args) {
        LinkListStack linkListStack = new LinkListStack();
        linkListStack.push(1);
        linkListStack.push(2);
        linkListStack.push(3);
        System.out.println(linkListStack.pop());
        System.out.println(linkListStack.pop());
        System.out.println(linkListStack.pop());
        System.out.println(linkListStack.peek());
        System.out.println(linkListStack.isEmpty());

    }
}

class LinkListStack {
    private final LinkListStackNode headNode;

    public LinkListStack() {
        headNode = new LinkListStackNode(0, null);
    }

    
    public void push(int value) {
        headNode.next = new LinkListStackNode(value, headNode.next);
    }

    
    public int pop() {
        if (isEmpty()) {
            throw new RuntimeException("栈空");
        }
        int value = headNode.next.value;
        headNode.next = headNode.next.next;
        return value;
    }

    
    public boolean isEmpty() {
        return headNode.next == null;
    }

    
    public Integer peek() {
        return headNode.next == null ? null : headNode.next.value;
    }


}


class LinkListStackNode {
    public int value;
    public LinkListStackNode next;

    public LinkListStackNode(int value, LinkListStackNode next) {
        this.value = value;
        this.next = next;
    }
}