The document describes methods for inserting nodes into a binary search tree and traversing it to print the nodes in different orders. The Insert method searches the tree and inserts new nodes in the left or right child position depending on if the data is less than or greater than the current node's data. It recursively searches the tree to find the correct insertion point. The PrintInOrder, PrintPreOrder and PrintPostOrder methods recursively traverse the tree to print the nodes in in-order, pre-order and post-order respectively.

1. // insert into sorted tree
void Trees::Insert(char data)
{
// when root is uninitialized
if (!head)
head = new Node(data);
else
{
Node* currentNode = head;
// search for the place to insert the new value
while (true)
{
// compare char values lt
if (currentNode->data < data)
{
// if the current node already has left child move and continue
if (currentNode->leftChild)
currentNode = currentNode->leftChild;
else // else create and insert
{
currentNode->leftChild = new Node(data);
return;
}
}
// compare char values gt
else
{
// if the current node alraedy has a right child move and continue
if (currentNode->rightChild)
currentNode = currentNode->rightChild;
else // else create and insert
{
currentNode->rightChild = new Node(data);
return;
}
}
}
}
}
void Trees::PrintInOrder(Node* head)
{
if (!head) return;
// non-recursive
#if 0
Node* currNode = head;
list<Node*> dataQ;
while (true)
{
if (currNode)
{
dataQ.push_back(currNode);
currNode = currNode->leftChild;
}
else
{
if (!dataQ.empty())
{
currNode = dataQ.back();
dataQ.pop_back();
cout << currNode->data << " ";

2. currNode = currNode->rightChild;
}
else break;
}
}
#endif
// recursive
#if 1
PrintInOrder(head->leftChild);
cout << head->data << " ";
PrintInOrder(head->rightChild);
#endif
}
void Trees::PrintPreOrder(Node* head)
{
if (!head) return;
cout << head->data << " ";
PrintInOrder(head->leftChild);
PrintInOrder(head->rightChild);
}
void Trees::PrintPostOrder(Node* head)
{
if (!head) return;
PrintInOrder(head->leftChild);
PrintInOrder(head->rightChild);
cout << head->data << " ";
}