节点在递归调用中未作为父节点传递而不更新(Node passed as a parent node in recursive call not updating)

节点在递归调用中未作为父节点传递而不更新(Node passed as a parent node in recursive call not updating) public class LinkedList{ private class Node{ int value; Node next; } private Node root; public LinkedList(){ root = null; } public void insert(int value){ root = insert(root, root, value); } public Node insert(Node node, Node parent, int value){ if(root == null){ node = new Node(); node.value = value; }else if(node == null){ node = new Node(); node.value = value; parent.next = null; }else{ node.next = insert(node.next, node, value); } return node; } public void printAll(){ printAll(root); } public void printAll(Node node){ Node traverse = node; while(traverse != null){ System.out.println("This node's value is " + traverse.value); traverse = traverse.next; } } public static void main(String[] args){ LinkedList myList = new LinkedList(); myList.insert(5); myList.insert(2); myList.printAll(); } }

这是一个解释我的麻烦的程序。 我有一个插入函数，它既有当前节点又有父节点作为参数。 对于第一次插入，我在列表中插入5，root基本上成为带有5的节点。对于第二次插入，我将2插入到列表中，但这次应该将其父节点设置为null。

当我在两次插入后打印时，它应该显示

This node's value is 5

但相反，它仍然显示父级的下一个仍然链接到第二个节点。

This node's value is 5 This node's value is 2

为什么我的parent.next = null不生效？ 有没有办法来解决这个问题？ 我有一个实现，需要能够修改父。

public class LinkedList{ private class Node{ int value; Node next; } private Node root; public LinkedList(){ root = null; } public void insert(int value){ root = insert(root, root, value); } public Node insert(Node node, Node parent, int value){ if(root == null){ node = new Node(); node.value = value; }else if(node == null){ node = new Node(); node.value = value; parent.next = null; }else{ node.next = insert(node.next, node, value); } return node; } public void printAll(){ printAll(root); } public void printAll(Node node){ Node traverse = node; while(traverse != null){ System.out.println("This node's value is " + traverse.value); traverse = traverse.next; } } public static void main(String[] args){ LinkedList myList = new LinkedList(); myList.insert(5); myList.insert(2); myList.printAll(); } }

Here is a program explaining my troubles. I have an insert function that has both the current node and the parent node as parameters. For the first insertion, I insert 5 into the list, the root basically becomes the Node with 5. For the second insertion, I insert 2 into the list, but this time it is supposed to set its parent node's next to null.

When I print after both insertions, it should display

This node's value is 5

But instead, it still shows that the parent's next is still link to the 2nd node.

This node's value is 5 This node's value is 2

Why doesn't my parent.next = null take effect? Is there a way to fix this? I have an implementation that requires the ability to modify the parent.

最满意答案

您在插入第一个节点时传递null，null。 然后，将返回哪个节点公共Node insert(Node node, Node parent, int value) 。 再看看

public void insert(int value){ root = insert(root, root, value); }

You are passing null,null when inserting the first node. Then, which node public Node insert(Node node, Node parent, int value) will return. Take a look again

public void insert(int value){ root = insert(root, root, value); }