Thread: need a little help here please!

i'v e got a program on binary search trees containing strings which are read from a file and put into the tree but
when i compile it i get the message -Error opening file- even though i have a file created
so has any one got any ideas ?

i also need to write a quick sort function for this program can you help me with it??? thanx

Code:

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#define WORD_SIZE 30

/*
   program to read a set of words from a file, store them in a binary
   search tree and then preform an in-order traversal of the tree
   during traversal contents of nodes are displayed - word and count

   assumes potential duplicates in original file; only writes one copy
   back
*/

typedef struct Treenode
        {
	char word[WORD_SIZE];
	int count;

	struct Treenode *left;
	struct Treenode *right;
        } Treenode;

Treenode* new_node(Treenode*, char*);
void inorder(Treenode*);
void to_file_preorder(Treenode*, FILE*);
void menu();
void check_choice(Treenode* tree, char);
void search(Treenode* tree,char*);
Treenode* del_node(Treenode* tree, char*);


int main()
   {
   char	str[30];
   FILE* fptr;
   int check =0;
   char ch;

   Treenode* root =NULL;
	

   if ( (fptr = fopen("test.txt","r")) == NULL)
       {
       fprintf(stderr, "Error in opening file test.txt");
       return(0);
       }
	
   while(fscanf(fptr, "%s", str) != EOF)
        root = new_node(root, str);

   menu();
   scanf(" %c", &ch);

 
   while ((ch != 'e') && (ch != 'E'))
	{
	 check_choice(root, ch);	
	menu();
        scanf(" %c", &ch);
        }



   fclose(fptr);

   if ( (fptr = fopen("test.txt","w")) == NULL)
       {
       fprintf(stderr, "Error in opening file test.txt for writing");
       return(0);
       }
   to_file_preorder(root, fptr);
   fclose(fptr);
   return(1);
   }


Treenode* new_node(Treenode* root, char word[30])
     {
     if(root == NULL)
	{
	root = (Treenode *) malloc(sizeof(Treenode));
	strcpy(root->word, word);		
	root->left = NULL;
	root->right = NULL;
	root->count = 1;
	}
	
	else
	   {
	   if((strcmp(word,root->word))==0)
		{
                root->count++;
		}
		else if((strcmp(word,root->word)) < 0)
		    {
		    root->left = new_node(root->left, word);
		    }
		else if((strcmp(word,root->word)) > 0)
		    {
		    root->right = new_node(root->right, word);
		    }
	    }
       return(root);
     }

void search(Treenode *root, char *term)
	{
	int l;

	if (root == NULL)
		{
		printf("Term not found\n");	
		return;
		}
	else if ((l = strcmp (root->word, term)) == 0)
		{
		printf("Term found in tree\n");
		return;
		}
	else if	(l > 0)
		search(root->left, term);
	else 
		search(root->right, term);
	}

void inorder(Treenode* root)
    {
	if(root != NULL)
	{
		inorder(root->left);
		printf("\n %s %d",root->word, root->count);
		inorder(root->right);
	}
}


void  to_file_preorder(Treenode *root, FILE *fptr)
	{
	if (root != NULL)
		{
		fprintf(fptr, "%s ",root->word);
		to_file_preorder(root->left, fptr);
		to_file_preorder(root->right, fptr);
		}
	}


void menu()
	{
	
	printf("\n\tExit program (e)\n");
	printf("\tview tree (v)\n");
	printf("\tSearch tree for string (s)\n");
	printf("\tAdd new string to tree (a)\n");
	printf("\tDelete string from tree(d)\n");
	return;

	}

void check_choice(Treenode *tree, char choice)
	{
	char term[WORD_SIZE];

	switch(choice)
		{
		case 'e' : printf("Exiting ...\n");
		      break;
		case 'v' : inorder(tree);
			   break;
                case 's' : printf("Please enter search term\n");
			   scanf ("%s", term);
			   search(tree, term);
			   break;
                case 'a' : printf("Please enter term to be added\n");
			   scanf ("%s", term);
			   tree = new_node(tree, term);
			   break;
				case 'd':  printf("Please enter term to be deleted\n");
					scanf("%s", &term);
					tree=del_node(tree,term);
					break;

		}
	
	}



//begin del_node function
Treenode* del_node(Treenode *T, char *term)
{
	Treenode *tmp, *tmp1, *prev1, *prev;
	int l;
	int found = 0; //boolean variable
	int direction;
	int delete_root = 0;


	tmp = prev = T;
	//search for node to be deleted
	while((tmp!=NULL) && (!found))
	{
		if((l = strcmp(tmp->word,term))==0)
			found = 1;
		else if(l>0)
		{
			prev = tmp;
			tmp = tmp->left;
			direction = 0;
		}
		else
		{
			prev = tmp;
			tmp = tmp->right;
			direction = 1;
		}

	}

	if(!found)
	{
		fprintf(stderr, "Value not found in tree\n");
			return(T);
	}

	if(tmp==T)
	{
		delete_root = 1;
	}

	//node to be deleted is pointed to by tmp; it's parent by prev;
	//case 1: no children
	if((tmp->left==NULL) && (tmp->right==NULL))
	{
		if(delete_root)
		{
			free(T);
			return(NULL);
		}
		if(direction==1)
			prev->right=NULL;
		else
			prev->left=NULL;
		free(tmp);
		return(T);
	}

	//case 2: one child
	if((tmp->left!=NULL) && (tmp->right==NULL))
	{
		if(delete_root)
		{
			tmp=tmp->left;
			free(prev);
			return(tmp);
		}
		if(direction==1)
			prev->right=tmp->left;
		else
			prev->left=tmp->left;
		free(tmp);
		return(T);
	}
	if((tmp->left==NULL) && (tmp->right!=NULL))
	{
		if(delete_root)
		{
			tmp=tmp->right;
			free(prev);
			return(tmp);
		}
		if(direction==1)
			prev->right=tmp->right;
		else
			prev->left=tmp->right;
		free(tmp);
		return(T);
	}


	//case 3: two children

	if((tmp->left!=NULL) && (tmp->right!=NULL))
	{
		direction = 0;
		prev1=tmp;
		tmp1=tmp->right;

		//find value to move up the tree
		while(tmp1->left!=NULL)
		{
			direction = 1;
			prev1 = tmp1;
			tmp1 = tmp1->left;
		}


		//move it ot place of value being deleted

		tmp->count=tmp1->count;
		strcpy(tmp->word,tmp1->word);

		//remove this value from its original location
		if(direction)
			prev1->left=NULL;
		else
			prev1->right=NULL;
		free(tmp1);
		return(T);
	}
	

}

thanx for taking the time to look at the program ,i actually tried to work on it this evening and finally got it to run,.
is there anyway that you can help me with a quicksort function that will go with the program?
thanx.