AVL Tree (C++)

/* Adelson Velseky Landis Tree */

# include
# include
# include

struct node
{
int element;
node *left;
node *right;
int height;
};

typedef struct node *nodeptr;

class bstree
{

public:
void insert(int,nodeptr &);
void del(int, nodeptr &);
int deletemin(nodeptr &);
void find(int,nodeptr &);
nodeptr findmin(nodeptr);
nodeptr findmax(nodeptr);
void copy(nodeptr &,nodeptr &);
void makeempty(nodeptr &);
nodeptr nodecopy(nodeptr &);
void preorder(nodeptr);
void inorder(nodeptr);
void postorder(nodeptr);
int bsheight(nodeptr);
nodeptr srl(nodeptr &);
nodeptr drl(nodeptr &);
nodeptr srr(nodeptr &);
nodeptr drr(nodeptr &);
int max(int,int);
int nonodes(nodeptr);
};

// Inserting a node
void bstree::insert(int x,nodeptr &p)
{
if (p == NULL)
{
p = new node;
p->element = x;
p->left=NULL;
p->right = NULL;
p->height=0;
if (p==NULL)
cout<<"Out of Space";
}
else
{
if (xelement)
{
insert(x,p->left);
if ((bsheight(p->left) - bsheight(p->right))==2)
{
if (x < p->left->element)
p=srl(p);
else
p = drl(p);
}
}
else if (x>p->element)
{
insert(x,p->right);
if ((bsheight(p->right) - bsheight(p->left))==2)
{
if (x > p->right->element)
p=srr(p);
else
p = drr(p);
}
}
else
cout<<"Element Exists";
}
int m,n,d;
m=bsheight(p->left);
n=bsheight(p->right);
d=max(m,n);
p->height = d + 1;

}

// Finding the Smallest
nodeptr bstree::findmin(nodeptr p)
{
if (p==NULL)
{
cout<<"
Empty Tree
";
return p;
}
else
{
while(p->left !=NULL)
p=p->left;
return p;
}
}

// Finding the Largest
nodeptr bstree::findmax(nodeptr p)
{
if (p==NULL)
{
cout<<"
Empty Tree
";
return p;
}
else
{
while(p->right !=NULL)
p=p->right;
return p;
}
}

// Finding an element
void bstree::find(int x,nodeptr &p)
{
if (p==NULL)
cout<<"
Element not found
";
else
if (x < p->element)
find(x,p->left);
else
if (x>p->element)
find(x,p->right);
else
cout<<"
Element found !
";

}

// Copy a tree
void bstree::copy(nodeptr &p,nodeptr &p1)
{
makeempty(p1);
p1 = nodecopy(p);
}

// Make a tree empty
void bstree::makeempty(nodeptr &p)
{
nodeptr d;
if (p != NULL)
{
makeempty(p->left);
makeempty(p->right);
d=p;
free(d);
p=NULL;
}
}

// Copy the nodes
nodeptr bstree::nodecopy(nodeptr &p)
{
nodeptr temp;
if (p==NULL)
return p;
else
{
temp = new node;
temp->element = p->element;
temp->left = nodecopy(p->left);
temp->right = nodecopy(p->right);
return temp;
}
}

// Deleting a node
void bstree::del(int x,nodeptr &p)
{
nodeptr d;
if (p==NULL)
cout<<"Element not found
";
else if ( x < p->element)
del(x,p->left);
else if (x > p->element)
del(x,p->right);
else if ((p->left == NULL) && (p->right == NULL))
{
d=p;
free(d);
p=NULL;
cout<<"
Element deleted !
";
}
else if (p->left == NULL)
{
d=p;
free(d);
p=p->right;
cout<<"
Element deleted !
";
}
else if (p->right == NULL)
{
d=p;
p=p->left;
free(d);
cout<<"
Element deleted !
";
}
else
p->element = deletemin(p->right);
}

int bstree::deletemin(nodeptr &p)
{
int c;
cout<<"inside deltemin
";
if (p->left == NULL)
{
c=p->element;
p=p->right;
return c;
}
else
{
c=deletemin(p->left);
return c;
}
}

void bstree::preorder(nodeptr p)
{
if (p!=NULL)
{
cout<element<<"-->";
preorder(p->left);
preorder(p->right);
}
}

// Inorder Printing
void bstree::inorder(nodeptr p)
{
if (p!=NULL)
{
inorder(p->left);
cout<element<<"-->";
inorder(p->right);
}
}

// PostOrder Printing
void bstree::postorder(nodeptr p)
{
if (p!=NULL)
{
postorder(p->left);
postorder(p->right);
cout<element<<"-->";
}
}

int bstree::max(int value1, int value2)
{
return ((value1 > value2) ? value1 : value2);
}

int bstree::bsheight(nodeptr p)
{
int t;
if (p == NULL)
return -1;
else
{
t = p->height;
return t;
}
}

nodeptr bstree:: srl(nodeptr &p1)
{
nodeptr p2;
p2 = p1->left;
p1->left = p2->right;
p2->right = p1;
p1->height = max(bsheight(p1->left),bsheight(p1->right)) + 1;
p2->height = max(bsheight(p2->left),p1->height) + 1;
return p2;
}

nodeptr bstree:: srr(nodeptr &p1)
{
nodeptr p2;
p2 = p1->right;
p1->right = p2->left;
p2->left = p1;
p1->height = max(bsheight(p1->left),bsheight(p1->right)) + 1;
p2->height = max(p1->height,bsheight(p2->right)) + 1;
return p2;
}


nodeptr bstree:: drl(nodeptr &p1)
{
p1->left=srr(p1->left);
return srl(p1);
}

nodeptr bstree::drr(nodeptr &p1)
{
p1->right = srl(p1->right);
return srr(p1);
}

int bstree::nonodes(nodeptr p)
{
int count=0;
if (p!=NULL)
{
nonodes(p->left);
nonodes(p->right);
count++;
}
return count;

}



int main()
{
clrscr();
nodeptr root,root1,min,max;//,flag;
int a,choice,findele,delele,leftele,rightele,flag;
char ch='y';
bstree bst;
//system("clear");
root = NULL;
root1=NULL;
cout<<"
AVL Tree
";
cout<<" ========
";
do
{
cout<<"
1.Insertion
2.FindMin
";
cout<<"3.FindMax
4.Find
5.Copy
";
cout<<"6.Delete
7.Preorder
8.Inorder
";
cout<<" 9.Postorder
10.height
";
cout<<"
Enter the choice:
";
cin>>choice;
switch(choice)
{
case 1:
cout<<"
New node's value ?
";
cin>>a;
bst.insert(a,root);
break;
case 2:
if (root !=NULL)
{
min=bst.findmin(root);
cout<<"
Min element : "<element;
}
break;
case 3:
if (root !=NULL)
{
max=bst.findmax(root);
cout<<"
Max element : "<element;
}
break;
case 4:
cout<<"
Search node :
";
cin>>findele;
if (root != NULL)
bst.find(findele,root);
break;
case 5:
bst.copy(root,root1);
bst.inorder(root1);
break;
case 6:
cout<<"Delete Node ?
";
cin>>delele;
bst.del(delele,root);
bst.inorder(root);
break;

case 7:
cout<<"
Preorder Printing... :
";
bst.preorder(root);
break;

case 8:
cout<<"
Inorder Printing.... :
";
bst.inorder(root);
break;

case 9:
cout<<"
Postorder Printing... :
";
bst.postorder(root);
break;
case 10:
cout<<"
Height and Depth is
";
cout< cout<<"No. of nodes:- "< break;



}
cout<<"
Do u want to continue (y/n) ?
";
cin>>ch;
}while(ch=='y');


return 0;
}