Hi everyone,

I have to display a binary search tree in a tree format.

For BST insertion, if the input contains the following

F
D
R
P
V
M
N

The resulting BST should be displayed as:

``````F
+-- D
|    +-- NULL
|    \-- NULL
\-- R
+-- P
|    +-- M
|    |    +-- NULL
|    |    \-- N
|    |         +-- NULL
|    |         \-- NULL
|    \-- NULL
\-- V
+-- NULL
\-- NULL``````

Completely depends on what you know. Since you gave us no hint (i.e. code) there's not much to explain.

I know how to print the data in preorder.....but i dont know how to display nodes in a tree format...

``````#include <iostream>
#include <cstdlib>
using namespace std;

class BinarySearchTree
{
private:
struct tree_node
{
tree_node* left;
tree_node* right;
int data;
};
tree_node* root;
public:
BinarySearchTree()
{
root = NULL;
}
bool isEmpty() const { return root==NULL; }
void print_inorder();
void inorder(tree_node*);
void print_preorder();
void preorder(tree_node*);
void print_postorder();
void postorder(tree_node*);
void insert(int);
void remove(int);
};

// Smaller elements go left
// larger elements go right
void BinarySearchTree::insert(int d)
{
tree_node* t = new tree_node;
tree_node* parent;
t->data = d;
t->left = NULL;
t->right = NULL;
parent = NULL;
// is this a new tree?
if(isEmpty()) root = t;
else
{
//Note: ALL insertions are as leaf nodes
tree_node* curr;
curr = root;
// Find the Node's parent
while(curr)
{
parent = curr;
if(t->data > curr->data) curr = curr->right;
else curr = curr->left;
}

if(t->data < parent->data)
parent->left = t;
else
parent->right = t;
}
}

void BinarySearchTree::remove(int d)
{
//Locate the element
bool found = false;
if(isEmpty())
{
cout<<" This Tree is empty! "<<endl;
return;
}
tree_node* curr;
tree_node* parent;
curr = root;
while(curr != NULL)
{
if(curr->data == d)
{
found = true;
break;
}
else
{
parent = curr;
if(d>curr->data) curr = curr->right;
else curr = curr->left;
}
}
if(!found)
{
return;
}

// 3 cases :
// 1. We're removing a leaf node
// 2. We're removing a node with a single child
// 3. we're removing a node with 2 children

// Node with single child
if((curr->left == NULL && curr->right != NULL)|| (curr->left != NULL
&& curr->right == NULL))
{
if(curr->left == NULL && curr->right != NULL)
{
if(parent->left == curr)
{
parent->left = curr->right;
delete curr;
}
else
{
parent->right = curr->right;
delete curr;
}
}
else // left child present, no right child
{
if(parent->left == curr)
{
parent->left = curr->left;
delete curr;
}
else
{
parent->right = curr->left;
delete curr;
}
}
return;
}

//We're looking at a leaf node
if( curr->left == NULL && curr->right == NULL)
{
if(parent->left == curr) parent->left = NULL;
else parent->right = NULL;
delete curr;
return;
}

//Node with 2 children
// replace node with smallest value in right subtree
if (curr->left != NULL && curr->right != NULL)
{
tree_node* chkr;
chkr = curr->right;
if((chkr->left == NULL) && (chkr->right == NULL))
{
curr = chkr;
delete chkr;
curr->right = NULL;
}
else // right child has children
{
//if the node's right child has a left child
// Move all the way down left to locate smallest element

if((curr->right)->left != NULL)
{
tree_node* lcurr;
tree_node* lcurrp;
lcurrp = curr->right;
lcurr = (curr->right)->left;
while(lcurr->left != NULL)
{
lcurrp = lcurr;
lcurr = lcurr->left;
}
curr->data = lcurr->data;
delete lcurr;
lcurrp->left = NULL;
}
else
{
tree_node* tmp;
tmp = curr->right;
curr->data = tmp->data;
curr->right = tmp->right;
delete tmp;
}

}
return;
}

}

void BinarySearchTree::print_inorder()
{
inorder(root);
}

void BinarySearchTree::inorder(tree_node* p)
{
if(p != NULL)
{
if(p->left) inorder(p->left);
cout<<"+--";
cout<<p->data<<endl;
if(p->right) inorder(p->right);
}
else return;
}

void BinarySearchTree::print_preorder()
{
preorder(root);
}

void BinarySearchTree::preorder(tree_node* p)
{
if(p != NULL)
{
cout<<" "<<p->data<<" ";
if(p->left) preorder(p->left);
if(p->right) preorder(p->right);
}
else return;
}

void BinarySearchTree::print_postorder()
{
postorder(root);
}

void BinarySearchTree::postorder(tree_node* p)
{
if(p != NULL)
{
if(p->left) postorder(p->left);
if(p->right) postorder(p->right);
cout<<" "<<p->data<<" ";
}
else return;
}

int main()
{
BinarySearchTree b;
int ch,tmp,tmp1;
while(1)
{
cout<<endl<<endl;
cout<<" Binary Search Tree Operations "<<endl;
cout<<" ----------------------------- "<<endl;
cout<<" 1. Insertion/Creation "<<endl;
cout<<" 2. In-Order Traversal "<<endl;
cout<<" 3. Pre-Order Traversal "<<endl;
cout<<" 4. Post-Order Traversal "<<endl;
cout<<" 5. Removal "<<endl;
cout<<" 6. Exit "<<endl;
cout<<" Enter your choice : ";
cin>>ch;
switch(ch)
{
case 1 : cout<<" Enter Number to be inserted : ";
cin>>tmp;
b.insert(tmp);
break;
case 2 : cout<<endl;
cout<<" In-Order Traversal "<<endl;
cout<<" -------------------"<<endl;
b.print_inorder();
break;
case 3 : cout<<endl;
cout<<" Pre-Order Traversal "<<endl;
cout<<" -------------------"<<endl;
b.print_preorder();
break;
case 4 : cout<<endl;
cout<<" Post-Order Traversal "<<endl;
cout<<" --------------------"<<endl;
b.print_postorder();
break;
case 5 : cout<<" Enter data to be deleted : ";
cin>>tmp1;
b.remove(tmp1);
break;
case 6 : system("pause");
return 0;
break;
}
}
}``````

Try Breath First Search.
Google for the code, I think you should be able to find it online

Try Breath First Search.
Google for the code, I think you should be able to find it online

Cant find it!!!!!!!!!!!!!

It's a typo, he meant breadth-first search.

hmmm...i knw ...i misd it...

but i still cant find....
plz guyz reply wid a code...i have a submission due tmrw...

but i still cant find....

``Results 1 - 10 of about 3,840,000 for breadth-first search``

Google awaits. I don't really know much about them at all I was just clarifying his post.

Cant find it!!!!!!!!!!!!!

hmmm...i knw ...i misd it...

but i still cant find....
plz guyz reply wid a code...i have a submission due tmrw...

Cut with the baby talk. This is an adult forum.

Cut with the baby talk. This is an adult forum.

I am able to insert and print the data like if the nodes are F,D,E...then the output is

``````F
D
+--D
+--NULL
E
\--E
+--NULL
\--NULL
\NULL

But it should be displayed as

F
+--D
|    +--NULL
|     \--E
|         +--NULL
|          \--NULL
\NULL``````