C language:Removing a node from a BST of strings - c

Question

I'm trying to write a function, that will remove a node from the BST, which will be == with the word that the user inserts in the program, meaning that I ask the user, which word would he like to remove, he types that in and saves it under the variable key[MAX] in main. But something goes wrong when trying to delete the node, so my program just dies
#include<stdio.h>
#include<stdlib.h>
#include<string.h>
#define MAX 15
typedef struct BST
{
char data[MAX];
struct BST *left;
struct BST *right;
int count;
} node;
node *create();
void insert(node *,node *);
void preorder(node *);
struct BST *minValueNode(struct BST *node)
{
struct BST *current = node;
while (current && current->left != NULL)
current = current->left;
return current;
}
struct BST *deleteNode(struct BST *root, char key[MAX])
{
if (root == NULL)
return root;
int cmp_rezult=strcmp(root->data, key[MAX]);
if (key[MAX] < root->data[MAX])
root->left = deleteNode(root->left, key);
else if (key[MAX] > root->data[MAX])
root->right = deleteNode(root->right, key);
else
{
if (root->left == NULL)//it the node has no children or only 1
{
struct BST *temp = root->right;
free(root);
return temp;
}
else if (root->right == NULL)
{
struct BST *temp = root->left;
free(root);
return temp;
}
//if the node have 2 kids
struct BST *temp = minValueNode(root->right);
//sorting
root->data[MAX] = temp->data[MAX];
//deleting
root->right = deleteNode(root->right, temp->data[MAX]);
}
return root;
}
int main()
{
char key[MAX];
char ch;
node *root=NULL,*temp;
do
{
temp=create();
if(root==NULL)
{
root=temp;
}
else
{
insert(root,temp);
}
printf("\nDo you want to enter more(y/n)?");
ch=getch();
}
while(ch=='y'||ch=='Y');
printf("\nPreorder Traversal: ");
preorder(root);
printf("\nWho shall we delete:");
scanf("%s", &key[MAX]);
deleteNode(root, key[MAX]);
return 0;
}
node *create()
{
node *temp;
printf("\nEnter data:");
temp=(node*)malloc(sizeof(node));
fgets(&temp->data,MAX,stdin);
temp->left=temp->right=NULL;
temp->count=1;
return temp;
}
void insert(node *root,node *temp)
{
int cmp_rezult=strcmp(temp->data,root->data);
if(cmp_rezult<0)
{
if(root->left!=NULL)
insert(root->left,temp);
else
root->left=temp;
}
if(cmp_rezult>0)
{
if(root->right!=NULL)
insert(root->right,temp);
else
root->right=temp;
}
if(cmp_rezult==0)
{
root->count++;
}
}
void preorder(node *root)
{
if(root!=NULL)
{
printf("\n%s Repeats:%d time(s)",root->data, root->count);
preorder(root->left);
preorder(root->right);
}
}

Answer 1

This is basically the same code as above, but, in BST *deleteNode I've updated the code at cmp_result so now it's written correctly, after that I've updated the if statements under the cmp_result, also I've updated the code in the same function, going from root->data[MAX] = temp->data[MAX]; to strcpy(root->data,temp->data);, which is the correct way to do it
#include<stdio.h>
#include<stdlib.h>
#include<string.h>
#define MAX 15
typedef struct BST
{
char data[MAX];
struct BST *left;
struct BST *right;
int count;
} node;
node *create();
void insert(node *,node *);
void preorder(node *);
struct BST *minValueNode(struct BST *node)
{
struct BST *current = node;
while (current && current->left != NULL)
current = current->left;
return current;
}
struct BST *deleteNode(struct BST *root, char key[MAX])
{
if (root == NULL)
return root;
int cmp_result = strcmp(key, root->data);
if (cmp_result < 0)
root->left = deleteNode(root->left, key);
else if (cmp_result > 0)
root->right = deleteNode(root->right, key);
else
{
if (root->left == NULL)
{
struct BST *temp = root->right;
free(root);
return temp;
}
else if (root->right == NULL)
{
struct BST *temp = root->left;
free(root);
return temp;
}
struct BST *temp = minValueNode(root->right);
strcpy(root->data,temp->data);
root->right = deleteNode(root->right, temp->data);
}
return root;
}
int main()
{
char key[MAX];
char ch;
node *root=NULL,*temp;
do
{
temp=create();
if(root==NULL)
{
root=temp;
}
else
{
insert(root,temp);
}
printf("\nDo you want to enter more(y/n)?");
ch=getch();
}
while(ch=='y'||ch=='Y');
printf("\nPreorder Traversal: ");
preorder(root);
printf("\n\nWho shall we delete:");
fgets(key,MAX,stdin);
printf("\n%s", key);
deleteNode(root, key);
printf("\nPreorder Traversal: ");
preorder(root);
return 0;
}
node *create()
{
node *temp;
printf("\nEnter data:");
temp=(node*)malloc(sizeof(node));
fgets(temp->data,MAX,stdin);
temp->left=temp->right=NULL;
temp->count=1;
return temp;
}
void insert(node *root,node *temp)
{
int cmp_rezult=strcmp(temp->data,root->data);
if(cmp_rezult<0)
{
if(root->left!=NULL)
insert(root->left,temp);
else
root->left=temp;
}
if(cmp_rezult>0)
{
if(root->right!=NULL)
insert(root->right,temp);
else
root->right=temp;
}
if(cmp_rezult==0)
{
root->count++;
}
}
void preorder(node *root)
{
if(root!=NULL)
{
printf("\n%s Repeats:%d time(s)",root->data, root->count);
preorder(root->left);
preorder(root->right);
}
}