How to create a tree using linked lists?

Although this question can be found in every books of C++，but I still think it is too complicated. So I want to create an easier version using linked lists, however, I have to create a list class, which is in turn requiring to create a class as the tree does, so how can I settle it? IF I build a tree based on list class, is it valid in C++， hope someone can help me！

What tree are you going to build ? An AVL, a binary tree can be built easier and believe me you can't use a list to build a tree. Look at the definitions and properties of tree and list. Things are as clear as crystal. What do you think ?

A binary tree is not difficult:

Code:

---

class Node
{
public:
  Node(value) { nValue = value; pLeft = pRight = NULL; }

  Node* pLeft;
  Node* pRight;
  int nValue;  // or any other data
}

class Tree
{
public:
  Node* pRoot;
  Tree() { pRoot = NULL; }

  Node* search(int value); //...
  void createLeaf(int value); //...
  // ...
}

---

Thank you! I will have a try.

you can use lists to build a tree or to load tree structure from it but u must figure it out how to store data in colums. something like this:

Code:

---

NUM | NODE_ID | LEVEL | PARENT | NAME
1            836          0          NULL      root
2            33            1          836        node1
3            43            1          836        node2
4            77            2          33          node1_1

---

get the point?
after that u just have to write method that will load it in your TRee object
witch might look something like this

Code:

---

class oNode
{
 CString name;
 int ID;
 oNode *pparent;
 typdef vector<oNode*>my_child_nodes;
 my_child_nodes my_nodes;
 get ...
 set ...
 ...
};

class oTree
{
 typedef vector <oNode *>root_nodes;
 root_nodes root;
 oNode *find(ID);
 oNode *putnode(oNode *node_in)
};

---

where oTree::find is recursive function witch will return pointer on node you want to put more nodes in.
Hope this helps.

Thx！But which is more efficient？ the one using linked lists or just random storage by the "new" operator?
BTW, if I want to implement an expression tree, and wish to have unary and binary operator in it, should I turn to multiway trees？Can I just calculate the unary operator with its operand at once, then store it as one operand?