二叉树-如何删除元素； 爪哇

Question

node root=null;

public node delete(node node, int val) {
    if(node == null) {
      return node;
    }

    if(val < node.value) {
      node.left= delete(node.left, val);
    } else if(val > node.value) {
      node.right= delete(node.right, val);
    } else {
      if(node.left== null || node.right== null) {
        node temp = node.left!= null ? node.left: node.right;

        if(temp == null) {
          return null;
        } else {
          return temp;
        }
      } else {
    node next = getSuccessor(node);
        node.value= next.value;
        node.right= delete(node.right, next.value);
        return node;
      }
    }

    return node;
  }
public node getSuccessor(node node) {
    if(node == null) {
      return null;
    }

    node temp = node.right;

    while(temp.left!= null) {
      temp = temp.left;
    }

    return temp;
  }

this is my code and this is the class for the nodes:

public class node {
    int value;
   node left;
   node right;
}

I already have a working code to add values. the problem is, when i add values, and try to delete some of them with the code i just wrote here, it's not working. this is what i put in main class when i try to delete a value:

binarytree tree= new binarytree;
node root=null;
root=tree.delete(root,4);

does anyone have any idea what could be wrong? am i missing a function that refers to the delete one or something like that? please note i'm new to java so if you want to help me treat me as a beginner i'd really appreciate if someone could help me make my delete function work because now it's not doing anything at all...

EDIT:

Code to add values:

void recadd(node a, int val) {
    if (val<a.value) {
        if (a.left==null){
            a.left=new node (val);
        }
    }
    else
    {
        if(a.right==null) {
            a.right=new node(val);
        }
        else {
            recadd(a.right, val);
        }
    }
}

the code i use to call the add function:

void add(int val){
    node k = new node (val);
if (root==null)
{
    root = k;
}
else
{
    recadd(root, val);
}
}

as stated before, i can add values just fine, the problem occurs when i try to delete them.

Answer 1

Your code should work. Maybe something is wrong with how you are inserting elements. Can you please share your full code?