具有多个子节点和左右两个节点的二叉搜索树

Question

I want to make a binary tree like this as given in the image given below in C programming language.

Structure to make binary tree having two nodes is this -

struct node {
    int data;
    struct node* left;
    struct node* right;
};

But for making a tree with multiple childs, structure needs to change every time, so is there any way to make a structure that changes every time?

Answer 1

You can define a node like this:

struct node
{
    int data;
    node *firstChild;
    node *nextSibling;
};

And then,

1. First child is accessed this way: myNode->firstChild

2. Second child: myNode->firstChild->nextSibling

3. Nth child: myNode->firstChild->nextSibling->...->nextSibling

This will involve null checks and iteration when going through child nodes.

Answer 2

In C, you cannot make a structure change dynamically. But what you want (variable number of children in each node) can be achieved in a slightly roundabout way. If you want to preserve the left and right nodes as separate entities from the other children, you could have a binary tree that contains a linked list for all additional children of that node:

struct TreeNode
{
    int data;
    ChildNode *firstChild;
    TreeNode *left;
    TreeNode *right;
};

struct ChildNode
{
    int data;
    ChildNode *next;
};