Program Crashing

I need help with my program. It's a search engine just like the guy's in the thread before mine. Here's the code:

Code:

---

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

FILE *infile;
char search[10][30];

/* Structure used for BST */
struct tree_node{
        char data[30];
        int count;
        struct tree_node *left;
        struct tree_node *right;
};

/* Structure used for Link List */
struct node{
        char lname[30];
        char fname[30];
        char title[50];
        int hits[10];
        int score;
        struct tree_node *p;
        struct node *next;
} *list;

/* Function Prototypes */
void load();
void addinfo(struct node **head, char lname[], char fname[], char title[]);
void findspot(struct node **head, char data[], char lname[], char fname[], char title[]);
void adddata(struct tree_node **p, char data[]);
void printheight(struct node *head, char lname[], char fname[], char title[]);
int findheight(struct tree_node *p);
void printwords(struct node *head, char lname[], char fname[], char title[]);
void print(struct tree_node *p);
void query();
void find(struct node **head, int count);
int findhits(struct tree_node *p, int i);
void findscore(struct node **head, int count);
void printresults(struct node **head, int count);

int main(){
        int option;
       
        do{
                /* Ask user pick option */
                printf("List of options: \n");
                printf("\t1. Load\n");
                printf("\t2. Query\n");
                printf("\t3. Quit\n");
                printf("\nEnter choice: ");
                scanf("%d", &option);
       
                /* Check option and do appropriate actions */
                switch(option){
                        case 1: /* Load */
                                load();
                                break;
               
                        case 2: /* Query */
                                query();
                                break;
                       
                        case 3: /* Quit */
                                printf("You have choosen Quit.\n");
                                break;
       
                        default: /* Invalid */
                                printf("Invalid choice. Please try again.\n");
                                break;
                }
        }while(option != 3);
       
        return 0;       
}

void load(){
        char file[30], fname[30], lname[30], title[50], data[30];
        int i, j, num, words = 0, length;
       
        /*  Get name of load file */
        do{
                printf("Name the load file: ");
                scanf("%s", file);
                infile = fopen(file, "r");
                putchar('\n');
        }while(!infile);
       
        /* Get num of documents */
        fscanf(infile, "%d", &num);
       
        /* Add info to documents */
        for(i = 0; i < num; i++){
                fscanf(infile, "%s %s", lname, fname);
                fscanf(infile, "%s", title);
                addinfo(&list, lname, fname, title);
               
                printf("%s\n", title);
                fscanf(infile, "%s", data);
       
                while(strcmp(data, "DOCUMENT_OVER") != 0){
                        words++;
                        length = strlen(data);
                       
                        /* Make word lower case */
                        for(j = 0; j < length; j++){
                                data[j] = tolower(data[j]);       
                        }
                       
                        findspot(&list, data, lname, fname, title);
                        fscanf(infile, "%s", data);
                }
               
                /* Print remaining info for document */
                printf("%d words\n", words);
                printheight(list, lname, fname, title);
                printwords(list, lname, fname, title);
        }
       
        fclose(infile);
}

/* Query the documents */
void query(){
        int count = 0;
        char file[30], data[30];
       
        /* Open the query file */
        do{
                printf("Name the query file: ");
                scanf("%s", file);
                infile = fopen(file, "r");
                putchar('\n');
        }while(!infile);
       
        fscanf(infile, "%s", data);
       
        /* Read in all the words */
        while(strcmp(data, "QUERY_OVER") != 0){
                strcpy(search[count], data);
                count++;
                fscanf(infile, "%s", data);
        }
       
        /* Find hits and scores then print results */
        find(&list, count);
        findscore(&list, count);
        printresults(&list, count);
       
        fclose(infile);
}
       
/* Add First and Last name along with the title to the node */
void addinfo(struct node **head, char lname[], char fname[], char title[]){
        struct node *pNew, *pCur, *pNext;
       
        pNew = (struct node*) (malloc(sizeof(struct node)));
        strcpy(pNew -> lname, lname);
        strcpy(pNew -> fname, fname);
        strcpy(pNew -> title, title);
        pNew -> next = NULL;
        pNew -> p = NULL;

        /* check if the list is empty or if next node is empty */
        if (*head == NULL)
                *head = pNew;

        else if((*head) -> next == NULL)
                (*head) -> next = pNew;
               
        /* now examine the remaining list */
        else {
                pCur = *head;
       
                while(pCur -> next != NULL){
                                pCur = pCur -> next ;
                }
     
                pCur -> next = pNew;
        }
}

/* Find where to add the data */       
void findspot(struct node **head, char data[], char lname[], char fname[], char title[]){
        struct node *pCur;
        pCur = *head;
       
        while(pCur != NULL){
                /* Find the right node in the link list */
                if(strcmp(pCur -> lname, lname) == 0 && strcmp(pCur -> fname, fname) == 0 && strcmp(pCur -> title, title) == 0){
                        /* Add data to the BST */
                        adddata(&pCur -> p, data);
                        break;
                }
               
                pCur = pCur -> next;
        };
}

/* Add data to the BST */
void adddata(struct tree_node **p, char data[]){
        struct tree_node *pNew, *pCur;
       
        pNew = (struct tree_node*)(malloc(sizeof(struct tree_node)));
        strcpy(pNew -> data, data);
        pNew -> count = 0;
        pNew -> left = NULL;
        pNew -> right = NULL;
       
        /* Check if NULL */
        if(*p == NULL)
                *p = pNew;
               
        pCur = *p;
               
        /* Check where to put the data */
        if(strcmp(pCur -> data, data) == 0)
                pCur -> count = (pCur -> count) + 1;
               
        if(strcmp(pCur -> data, data) < 0)
                adddata(&pCur -> left, data);
               
        if(strcmp(pCur -> data, data) > 0)
                adddata(&pCur -> right, data);
}

/* Print height of the BST */
void printheight(struct node *head, char lname[], char fname[], char title[]){
        struct node *pCur = head;
        int height;
       
        /* If the list isn't null */
        if(pCur != NULL){
                if(strcmp(pCur -> lname, lname) == 0 && strcmp(pCur -> fname, fname) == 0 && strcmp(pCur -> title, title) == 0){
                        height = findheight(pCur -> p);
                        printf("Height %d\n", height);
                }
               
                else
                        printheight(pCur -> next, lname, fname, title);
        }
}

/* Find the height of the BST */
int findheight(struct tree_node *p){
        int left, right;
       
        /* If null return 0 */
        if(p == NULL)
                return 0;

        left = 1 + findheight(p -> left);
        right = 1 + findheight(p -> right);

        if (left > right)
                return left;
        else
                return right;
}

/* Find correct node for BST */
void printwords(struct node *head, char lname[], char fname[], char title[]){       
        struct node *pCur;
        pCur = head;
       
        /* If the list isn't null */
        if(pCur != NULL){
                if(strcmp(pCur -> lname, lname) == 0 && strcmp(pCur -> fname, fname) == 0 && strcmp(pCur -> title, title) == 0){
                        print(pCur -> p);
                        putchar('\n');
                        putchar('\n');
                }
                else
                        printwords(pCur -> next, lname, fname, title);
        }
}

/* Print the words in the BST */
void print(struct tree_node *p){
        struct tree_node *pCur = p;
       
        /* If p isn't null */
        if(pCur != NULL){
                if(pCur -> count > 1)
                        printf("%s(%d) ", pCur -> data, pCur -> count);
                else if(pCur -> count == 1)
                        printf("%s ", pCur -> data);
                       
                print(pCur -> left);
                print(pCur -> right);
        }
       
}

/* Find the amount of hits */
void find(struct node **head, int count){
        struct node *pCur = *head;
        int i;
       
        /* Assign the values */
        while(pCur != NULL){
                for(i = 0; i < count + 1; i++){
                        pCur -> hits[i] = findhits(pCur -> p, i);
                }

                pCur = pCur -> next;
        }
}       

/* Return the amount of hits */
int findhits(struct tree_node *p, int i){
        struct tree_node *pCur = p;       
       
        if(strcmp(pCur -> data, search[i]) == 0)
                return(pCur -> count);
               
        if(strcmp(pCur -> data, search[i]) < 0)
                findhits(pCur -> left, i);
               
        if(strcmp(pCur -> data, search[i]) > 0)
                findhits(pCur -> right, i);
}

/* Assign the scores */
void findscore(struct node **head, int count){
        struct node *pCur = *head;
        int i, j, length;
        char title[50];
       
        pCur -> score = 999;
       
        /* Assign the score based on hits */
        while(pCur != NULL){
                for(i = 0; i < count + 1; i++){
                        if(pCur -> hits[i] != 0){
                                if(pCur -> hits[i] < pCur -> score)
                                        pCur -> score = pCur -> hits[i];
                        }
                }
               
                pCur = pCur -> next;
                pCur -> score = 999;
        }
       
        pCur = *head;
       
        /* Add 10 if title matches */
        while(pCur != NULL){
                strcpy(title, pCur -> title);
                length = strlen(title);
                       
                /* Make word lower case */
                for(j = 0; j < length; j++){
                        if(isalpha(title[j]) && isupper(title[j]))
                                title[j] = tolower(title[j]);       
                }
               
                for(i = 0; i < count + 1; count++){
                        if(strcmp(title, search[i]) == 0);
                                pCur -> score = pCur -> score + 10;
                }
               
                pCur = pCur -> next;
        }
}

/* Print the results */
void printresults(struct node **head, int count){
        struct node *pNew = *head, *pCur = *head;
        int i, highest = 0;
       
        while(pNew != NULL){
                /* Find highest score */
                while(pCur != NULL){
                        if(highest < pCur -> score)
                                highest = pCur -> score;
               
                        pCur = pCur -> next;
                }
       
                pCur = *head;
       
                /* If the score isn't 0 */
                if(highest != 0){
                        while(pCur != NULL){
                                if(highest == pCur -> score)
                                        break;
                               
                                pCur = pCur -> next;
                        }
               
                        for(i = 0; i < count + 1; i++){
                                printf("%s ", search[i]);
                        }
               
                        printf("\nDocument: %s\n", pCur -> title);
                        printf("Author: %s %s\n", pCur -> fname, pCur -> lname);
               
                        for(i = 0; i < count + 1; i++){
                                if(pCur -> hits[i] != 0)
                                        printf("%s(%d) ", search[i], pCur -> hits[i]);
                        }
               
                        printf("\nScore: %d\n", pCur -> score);
                }
       
                pCur -> score = 0;
                pNew = pNew -> next;
        }
}

---

Here's the input:

Code:

---

2
Robin Jena
Stock_market
liquidity fiscal Quote debt funds price fiscal
venture quote trailing accounts fiscal diluted Inventory
analyst inventory yield Stock inventory DOCUMENT_OVER
William Boyd
Heart
nuclear cardio radiometry arthritis
heart patient ventricular patient treadmill wine
diagnosis yield analyst inventory yield yield
cardio analyst DOCUMENT_OVER

---

Here's the output:

Code:

---

List of options:
        1. Load
        2. Query
        3. Quit

Enter choice: 1
Name the load file: test.txt

Stock_market
19 words
Height 5
liquidity quote(2) venture yield trailing stock price fiscal(3) funds inventory(3) debt diluted accounts analyst

Heart
37 words
Height 5
nuclear radiometry ventricular wine yield(3) treadmill patient(2) cardio(2) heart inventory diagnosis arthritis analyst(2)

List of options:
        1. Load
        2. Query
        3. Quit

Enter choice: 2
Name the query file: query.txt

      0 [main] a 3768 handle_exceptions: Exception: STATUS_ACCESS_VIOLATION
  10683 [main] a 3768 stackdump: Dumping stack trace to a.exe.stackdump

 ----jGRASP cygwin wedge2: process died on signal 11.
 ----jGRASP: operation complete.

---

Now I've figured out that it's crashing in the findhits() function. I've played around with it for a long time and still can't get it to work. Does anyone have any ideas of how I could change that function to get the program working?

Just by looking at the findhits() function:

Code:

---

int findhits(struct tree_node *p, int i){
        struct tree_node *pCur = p;       
       
        if(strcmp(pCur -> data, search[i]) == 0)
                return(pCur -> count);
               
        if(strcmp(pCur -> data, search[i]) < 0)
                findhits(pCur -> left, i);
               
        if(strcmp(pCur -> data, search[i]) > 0)
                findhits(pCur -> right, i);
}

---

The obvious problem is when p becomes NULL. You have no code to check for that and what you did was simply dive in and derefence a NULL pointer which is a no-no. I could be wrong though since I just took a quick glance but it seems that the function would only work if the data actually was in the tree, otherwise it would eventually encounter a NULL and boom.

So perhaps you could check the value of p before having the if statements, if p == NULL then return a value to indicate it couldn't be found.

An observation, you seem to be looking for "QUERY_OVER" in your query() function, but I don't see that in your data file.

Ok, thanks for the help I got the program working. I know the code is probably poor and a jumbled mess but atleast it works. As for looking for "QUERY_OVER" I forgot to post that in my first post. That input file looks like:

Code:

---

heart yield patient QUERY_OVER

---

I made these changes to the findhits() function:

Code:

---

/* Return the amount of hits */
int findhits(struct tree_node *p, int i){
        struct tree_node *pCur = p;       
       
        if(pCur != NULL){
                if(strcmp(pCur -> data, search[i]) == 0)
                        return(pCur -> count);       
               
                else if(strcmp(pCur -> data, search[i]) < 0)
                        findhits(pCur -> left, i);
               
                else if(strcmp(pCur -> data, search[i]) > 0)
                        findhits(pCur -> right, i);
        }
}

---

I also had to make some adjustments to finescore() and printresults(). I had a few crashes there but I was able to fix those easily. I can't believe I forgot to check for NULL, I had been coding for hours and started making lots of mistakes.

Now that I've turned this in. Can anyone suggest a cleaner more effective way to code this using the binary search trees inside a linear link list? I can't help but to feel somehow that my code is ineffective. The tree wasn't suposed to be AVL for simplicities sake.