okay. So I have this code for AVL tree that works fine!
Code:
#include<stdio.h>
#include<stdlib.h>
typedef struct node
{
int *key;
struct node *left;
struct node *right;
int height;
}node ,*nodeptr;
int CompareIntegerDefault(int *data1,int * data2)
{
if(*data1>*data2)
return (1);
else if(*data1==*data2)
return (0);
else
return (-1);
}
// A utility function to get maximum of two integers
int max1(int a, int b);
// A utility function to get height of the tree
int height(struct node *N)
{
if (N == NULL)
return 0;
return N->height;
}
// A utility function to get maximum of two integers
int max1(int a, int b)
{
if(a>b)
return a;
else
return b;
// return (a > b)? a : b;
}
/* Helper function that allocates a new node with the given key and
NULL left and right pointers. */
struct node* newNode(int *key)
{
struct node* node = (struct node*)
malloc(sizeof(struct node));
node->key = key;
node->left = NULL;
node->right = NULL;
node->height = 1; // new node is initially added at leaf
return(node);
}
typedef struct ContainerHandle
{
struct node * root;
}ContainerHandle;
// A utility function to right rotate subtree rooted with y
// See the diagram given above.
struct node *rightRotate(struct node *y)
{
struct node *x = y->left;
struct node *T2 = x->right;
// Perform rotation
x->right = y;
y->left = T2;
// Update heights
y->height = max1(height(y->left), height(y->right))+1;
x->height = max1(height(x->left), height(x->right))+1;
// Return new root
return x;
}
// A utility function to left rotate subtree rooted with x
// See the diagram given above.
struct node *leftRotate(struct node *x)
{
struct node *y = x->right;
struct node *T2 = y->left;
// Perform rotation
y->left = x;
x->right = T2;
// Update heights
x->height = max1(height(x->left), height(x->right))+1;
y->height = max1(height(y->left), height(y->right))+1;
// Return new root
return y;
}
// Get Balance factor of node N
int getBalance(struct node *N)
{
if (N == NULL)
return 0;
return height(N->left) - height(N->right);
}
struct node* insert(struct node* node, void *key)
{
/* 1. Perform the normal BST rotation */
int balance;
if (node == NULL)
return(newNode(key));
if (CompareIntegerDefault(key , node->key)<0)
node->left = insert(node->left, key);
else
node->right = insert(node->right, key);
/* 2. Update height of this ancestor node */
node->height = max1(height(node->left), height(node->right)) + 1;
/* 3. Get the balance factor of this ancestor node to check whether
this node became unbalanced */
balance = getBalance(node);
// If this node becomes unbalanced, then there are 4 cases
// Left Left Case
if (balance > 1 && CompareIntegerDefault(key , node->left->key)<0)
return rightRotate(node);
// Right Right Case
if (balance < -1 && CompareIntegerDefault(key , node->right->key)>0)
return leftRotate(node);
// Left Right Case
if (balance > 1 && CompareIntegerDefault(key , node->left->key)>0)
{
node->left = leftRotate(node->left);
return rightRotate(node);
}
// Right Left Case
if (balance < -1 && CompareIntegerDefault(key , node->right->key)<0)
{
node->right = rightRotate(node->right);
return leftRotate(node);
}
/* return the (unchanged) node pointer */
return node;
}
void preOrder(struct node *root)
{
if(root != NULL)
{
printf("%d ",*(int *)(root->key));
preOrder(root->left);
preOrder(root->right);
}
}
int main()
{
ContainerHandle *hdl;
/* Constructing tree given in the above figure */
int a,b,c,d,e,f,g,i,j,k,l,m,n,o,p,q,r,s,t;
hdl=(ContainerHandle *)malloc(sizeof(ContainerHandle));
hdl->root=NULL;
a=9;
hdl->root=insert(hdl->root, &a);
b=5;
hdl->root=insert(hdl->root, &b);
c=10;
hdl->root=insert(hdl->root, &c);
d=0;
hdl->root=insert(hdl->root, &d);
e=6;
hdl->root=insert(hdl->root, &e);
f=11;
hdl->root=insert(hdl->root, &f);
g=-1;
hdl->root=insert(hdl->root, &g);
i=1;
hdl->root=insert(hdl->root, &i);
j=2;
hdl->root=insert(hdl->root, &j);
/* The constructed AVL Tree would be
9
/ \
1 10
/ \ \
0 5 11
/ / \
-1 2 6
*/
printf("Pre order traversal of the constructed AVL tree is \n");
preOrder(hdl->root);
return 0;
}
but I dont want the insert function to return a structure pointer( since I'm planning to make it return error codes.
so I did this
Code:
#include<stdio.h>
#include<stdlib.h>
typedef struct node
{
int *key;
struct node *left;
struct node *right;
int height;
}node ,*nodeptr;
int CompareIntegerDefault(int *data1,int * data2)
{
if(*data1>*data2)
return (1);
else if(*data1==*data2)
return (0);
else
return (-1);
}
// A utility function to get maximum of two integers
int max1(int a, int b);
// A utility function to get height of the tree
int height(struct node *N)
{
if (N == NULL)
return 0;
return N->height;
}
// A utility function to get maximum of two integers
int max1(int a, int b)
{
if(a>b)
return a;
else
return b;
// return (a > b)? a : b;
}
/* Helper function that allocates a new node with the given key and
NULL left and right pointers. */
struct node* newNode(int *key)
{
struct node* node = (struct node*)
malloc(sizeof(struct node));
node->key = key;
node->left = NULL;
node->right = NULL;
node->height = 1; // new node is initially added at leaf
return(node);
}
typedef struct ContainerHandle
{
struct node * root;
}ContainerHandle;
// A utility function to right rotate subtree rooted with y
// See the diagram given above.
struct node *rightRotate(struct node *y)
{
struct node *x = y->left;
struct node *T2 = x->right;
// Perform rotation
x->right = y;
y->left = T2;
// Update heights
y->height = max1(height(y->left), height(y->right))+1;
x->height = max1(height(x->left), height(x->right))+1;
// Return new root
return x;
}
// A utility function to left rotate subtree rooted with x
// See the diagram given above.
struct node *leftRotate(struct node *x)
{
struct node *y = x->right;
struct node *T2 = y->left;
// Perform rotation
y->left = x;
x->right = T2;
// Update heights
x->height = max1(height(x->left), height(x->right))+1;
y->height = max1(height(y->left), height(y->right))+1;
// Return new root
return y;
}
// Get Balance factor of node N
int getBalance(struct node *N)
{
if (N == NULL)
return 0;
return height(N->left) - height(N->right);
}
void insert(struct node** node, void *key)
{
/* 1. Perform the normal BST rotation */
int balance;
if ((*node) == NULL)
(*node)=newNode(key);
if (CompareIntegerDefault(key , (*node)->key)<0)
insert(&((*node)->left), key);
else
insert(&((*node)->right), key);
/* 2. Update height of this ancestor (*node) */
(*node)->height = max1(height((*node)->left), height((*node)->right)) + 1;
/* 3. Get the balance factor of this ancestor (*node) to check whether
this (*node) became unbalanced */
balance = getBalance((*node));
// If this (*node) becomes unbalanced, then there are 4 cases
// Left Left Case
if (balance > 1 && CompareIntegerDefault(key , (*node)->left->key)<0)
(*node)= rightRotate((*node));
// Right Right Case
if (balance < -1 && CompareIntegerDefault(key , (*node)->right->key)>0)
(*node)= leftRotate((*node));
// Left Right Case
if (balance > 1 && CompareIntegerDefault(key , (*node)->left->key)>0)
{
(*node)->left = leftRotate((*node)->left);
(*node)= rightRotate((*node));
}
// Right Left Case
if (balance < -1 && CompareIntegerDefault(key , (*node)->right->key)<0)
{
(*node)->right = rightRotate((*node)->right);
(*node)= leftRotate((*node));
}
/* return the (unchanged) (*node) pointer */
}
void preOrder(struct node *root)
{
if(root != NULL)
{
printf("%d ",*(int *)(root->key));
preOrder(root->left);
preOrder(root->right);
}
}
int main()
{
ContainerHandle *hdl;
/* Constructing tree given in the above figure */
int a,b,c,d,e,f,g,i,j,k,l,m,n,o,p,q,r,s,t;
hdl=(ContainerHandle *)malloc(sizeof(ContainerHandle));
hdl->root=NULL;
a=9;
insert(&(hdl->root), &a);
b=5;
insert(&(hdl->root), &b);
c=10;
insert(&(hdl->root), &c);
d=0;
insert(&(hdl->root), &d);
e=6;
insert(&(hdl->root), &e);
f=11;
insert(&(hdl->root), &f);
g=-1;
insert(&(hdl->root), &g);
i=1;
insert(&(hdl->root), &i);
j=2;
insert(&(hdl->root), &j);
/* The constructed AVL Tree would be
9
/ \
1 10
/ \ \
0 5 11
/ / \
-1 2 6
*/
printf("Pre order traversal of the constructed AVL tree is \n");
preOrder(hdl->root);
return 0;
}
I get a warning:-
warning C4717: 'insert' : recursive on all control paths, function will cause runtime stack overflow.
I can't figure out why this doesn't work!!
Can someone please help me understand!
Thanks in advance!