createBinaryTree is giving an infinite Loop and createBinarySearchTree is giving segmentation Fault - data-structures

Question

createBinaryTree is giving an infinite Loop and createBinarySearchTree is giving segmentation Fault.
Could someone please guide me as I quite new to data structures.
#include <stdio.h>
#include <stdlib.h>
typedef struct node
{
int data;
struct node *lchild;
struct node *rchild;
} * NODE;
NODE createBinaryTree(NODE root)
{
NODE temp = (NODE)malloc(sizeof(struct node));
printf("Enter the value of the node. \n Enter -1 for returning. \n");
scanf(" %d", &temp->data);
if (temp->data == -1)
return NULL;
else
{
printf("For left Node of %d \n", temp->data);
temp->lchild = createBinaryTree(temp->lchild);
printf("For right Node of %d \n", temp->data);
temp->rchild = createBinaryTree(temp->rchild);
}
return temp;
}
NODE createBinarySearchTree(NODE root, int ele)
{
NODE new_node;
new_node = (NODE)malloc(sizeof(struct node));
new_node->data = ele;
new_node->lchild = new_node = NULL;
if (root == NULL)
return new_node;
NODE parent = NULL;
NODE curr = root;
while (curr != NULL)
{
parent = curr;
if (curr->data < ele)
curr = curr->rchild;
else
curr = curr->lchild;
}
if (ele < parent->data)
parent->lchild = new_node;
else
parent->rchild = new_node;
return root;
}
void inorder(NODE ptr)
{
if (ptr != NULL)
{
inorder(ptr->lchild);
printf("%5d", ptr->data);
inorder(ptr->rchild);
}
}
void postorder(NODE ptr)
{
if (ptr != NULL)
{
postorder(ptr->lchild);
postorder(ptr->rchild);
printf("%5d", ptr->data);
}
}
void preorder(NODE ptr)
{
if (ptr != NULL)
{
printf("%5d", ptr->data);
preorder(ptr->lchild);
preorder(ptr->rchild);
}
}
void main()
{
NODE root = NULL;
printf("Enter 0.createBinaryTree \n");
printf("Enter 1.createBinarySearchTree \n");
printf("Enter 2.displayTree \n");
printf("Enter 3.searchTree \n");
int choice;
printf("Enter your choice\n");
scanf(" %d", &choice);
int tempvalue;
while (1)
{
switch (choice)
{
case 0:
root = createBinaryTree(root);
break;
case 1:
printf("Enter Root Node\n");
scanf(" %d", &tempvalue);
while (tempvalue != -1)
{
root = createBinarySearchTree(root, tempvalue);
break;
printf("Enter Next Node.\n Enter -1 to exit\n");
scanf(" %d", &tempvalue);
}
break;
case 2:
printf("\n Inorder Traversals \n");
inorder(root);
printf("\n Postorder Traversals \n");
postorder(root);
printf("\n Preorder Traversals \n");
preorder(root);
printf("\n ********* \n");
break;
case 4:
exit(0);
}
}
}

Answer 1

For the BinarySearchTree. In the first iteration, you setting the new node to NULL in every iteration. It would be better to first check the value of the node and then decide, which direction to traverse the tree in. When you hit the root add the node. Something like the following.
Take input of root separately so that you can compare the next input.
case 1:
printf("Enter Root Node\n");
scanf(" %d", &tempvalue);
NODE root;
root = (NODE)malloc(sizeof(struct node));
root->data = tempvalue;
while (tempvalue != -1)
{
printf("Enter Node Value\n");
scanf(" %d", &value);
if(value == -1){
break;
}
root = createBinarySearchTree(root, value);
}
return 0;
Then inside the function,traverse the tree till you find where the node should go.
NODE createBinarySearchTree(NODE root, int ele)
{
NODE new_node;
new_node = (NODE)malloc(sizeof(struct node));
new_node->data = ele;
if (root == NULL)
return new_node;
NODE curr = root;
while (curr != NULL)
{
printf("%d\n",curr->data);
if(ele < curr->data )
{
if(curr->lchild == NULL){
printf("inserted %d as left child of %d\n",ele,curr->data );
curr->lchild = new_node;
return root;
}
curr=curr->lchild;
}
else if(ele > curr->data)
{
if(curr->rchild == NULL){
printf("inserted %d as right child child of %d\n",ele,curr->data );
curr->rchild = new_node;
return root;
}
curr=curr->rchild;
}
}
return root;
}

Answer 2

For your createBinaryTree function
The problem is with the line scanf(" %d", &temp->data); When you get to the root of the tree you then call create binary tree again on the the node above the root which then overwrites your earlier entry. To fix this you should check the value of scanf before assigning it to the temp->data. Also instead of return NULL on -1, you need to return root, in case root was set in previous iteration. Something like the following.
EDIT
typedef struct node
{
int data;
struct node *lchild;
struct node *rchild;
} * NODE;
NODE createBinaryTree(NODE root)
{
printf("Enter the value of the node. \n Enter -1 for returning. \n");
int input = 0;
scanf(" %d", &input);
printf("%d\n",input );
if(input == -1 && root == NULL){
return NULL;
}
if(input == -1 && root != NULL){
return root;
}
NODE temp = (NODE)malloc(sizeof(struct node));
temp->data = input;
if (temp->data == -1)
return NULL;
else
{
printf("For left Node of %d \n", temp->data);
temp->lchild = createBinaryTree(temp->lchild);
printf("For right Node of %d \n", temp->data);
temp->rchild = createBinaryTree(temp->rchild);
}
return temp;
}
NODE createBinarySearchTree(NODE root, int ele)
{
NODE new_node;
new_node = (NODE)malloc(sizeof(struct node));
new_node->data = ele;
new_node->lchild = new_node;
if (root == NULL)
return new_node;
NODE parent = NULL;
NODE curr = root;
while (curr != NULL)
{
parent = curr;
if (curr->data < ele)
curr = curr->rchild;
else
curr = curr->lchild;
}
if (ele < parent->data)
parent->lchild = new_node;
else
parent->rchild = new_node;
return root;
}
void inorder(NODE ptr)
{
if (ptr != NULL)
{
inorder(ptr->lchild);
printf("%5d", ptr->data);
inorder(ptr->rchild);
}
}
void postorder(NODE ptr)
{
if (ptr != NULL)
{
postorder(ptr->lchild);
postorder(ptr->rchild);
printf("%5d", ptr->data);
}
}
void preorder(NODE ptr)
{
if (ptr != NULL)
{
printf("%5d", ptr->data);
preorder(ptr->lchild);
preorder(ptr->rchild);
}
}
int main()
{
NODE root = NULL;
printf("Enter 0.createBinaryTree \n");
printf("Enter 1.createBinarySearchTree \n");
printf("Enter 2.displayTree \n");
printf("Enter 3.searchTree \n");
int choice;
printf("Enter your choice\n");
scanf(" %d", &choice);
int tempvalue;
while (1)
{
switch (choice)
{
case 0:
root = createBinaryTree(root);
printf("Done\n");
return 0;
case 1:
printf("Enter Root Node\n");
scanf(" %d", &tempvalue);
while (tempvalue != -1)
{
root = createBinarySearchTree(root, tempvalue);
break;
printf("Enter Next Node.\n Enter -1 to exit\n");
scanf(" %d", &tempvalue);
}
return 0;
case 2:
printf("\n Inorder Traversals \n");
inorder(root);
printf("\n Postorder Traversals \n");
postorder(root);
printf("\n Preorder Traversals \n");
preorder(root);
printf("\n ********* \n");
return 0;
case 4:
exit(0);
}
}
return 0;
}