java数据结构基础:单链表与双向链表

public class SingleNode {
	public int data;
	public SingleNode next;
	public SingleNode(int data) {
		this.data = data;
	}
	@Override
	public String toString() {
		return "SingleNode{" + "data=" + data + '}';
	}
}

public class SingleLinkedList {
	private SingleNode head = new SingleNode(0);
    //获取头结点
	public SingleNode getHead(){
		return head;
	}
	//添加节点
	public void add(SingleNode singleNode) {
		SingleNode temp = head;
		//找到链表最后一个节点
		while (temp.next != null) {
			temp = temp.next;
		}
		temp.next = singleNode;
	}
	//按顺序添加节点
	public void addByOrder(SingleNode singleNode) {
		SingleNode temp = head;
		while (true) {
			if (temp.next == null) {
				//已经遍历到链表最后了
				break;
			} else if (temp.next.data > singleNode.data) {
				//找到应插入的位置
				break;
			}
			temp = temp.next;
		}
		singleNode.next = temp.next;
		temp.next = singleNode;
	}
	//删除节点
	public void delete(int data) {
		SingleNode temp = head;
		boolean flag = false;    //标志是否找到待删除节点的前一个节点
		while (true) {
			if (temp.next == null) {
				//已经遍历到链表最后了
				break;
			} else if (temp.next.data == data) {
				//找到待删除节点的前一个节点
				flag = true;
				break;
			}
			temp = temp.next;
		}
		if (flag) {
			temp.next = temp.next.next;
		} else {
			System.out.println("要删除的节点不存在");
		}
	}
	//输出链表
	public void show() {
		//判断链表是否为空
		if (head.next == null) {
			System.out.println("链表为空");
			return;
		}
		SingleNode temp = head.next;
		while (temp != null) {
			System.out.println(temp);
			temp = temp.next;
		}
	}
}

public class DoubleNode {
	public int data;
	public DoubleNode next;
	public DoubleNode pre;
	public DoubleNode(int data) {
		this.data = data;
	}
	@Override
	public String toString() {
		return "DoubleNode{" + "data=" + data + '}';
	}
}

public class DoubleLinkedList {
	public DoubleNode head = new DoubleNode(0);
	//获取头结点
	public DoubleNode getHead() {
		return head;
	}
	//添加节点
	public void add(DoubleNode doubleNode) {
		DoubleNode temp = head;
		//找到链表最后一个节点
		while (temp.next != null) {
			temp = temp.next;
		}
		temp.next = doubleNode;
		doubleNode.pre = temp;
	}
	//删除节点
	public void delete(int data) {
		DoubleNode temp = head.next;
		boolean flag = false;    //标志是否找到待删除节点的前一个节点
		while (true) {
			if (temp == null) {
				//已经遍历到链表最后了
				break;
			} else if (temp.data == data) {
				//找到待删除节点
				flag = true;
				break;
			}
			temp = temp.next;
		}
		if (flag) {
			temp.pre.next = temp.next;
			if (temp.next != null) {
				//若删除节点不为最后一个节点
				temp.next.pre = temp.pre;
			}
		} else {
			System.out.println("要删除的节点不存在");
		}
	}
	//输出链表
	public void show() {
		//判断链表是否为空
		if (head.next == null) {
			System.out.println("链表为空");
			return;
		}
		DoubleNode temp = head.next;
		while (temp != null) {
			System.out.println(temp);
			temp = temp.next;
		}
	}
}