need help with my C code

record_llist.c

#include "record_llist.h"

#include

#include

#include

#include

NODE *new_node(int val) {

NODE *p = (NODE*)malloc(sizeof(NODE));

if(p != NULL) {

p->data = val;

p->next = NULL;

return p;

}

}

void display(NODE *start) {

if (start == NULL) return;

NODE *ptr = start;

while (ptr != NULL) {

printf("%d", ptr->data);

ptr = ptr->next;

}

}

NODE* search(NODE *start, char *name) {

NODE *ptr = *start;

while (ptr != start) {

if (strcmp(ptr->data.name, name) == 0)

return ptr;

ptr = ptr->next;

}

return NULL;

}

void insert(NODE **startp, char *name, float score) {

NODE *p = (NODE *) molloc(sizeof(NODE));

strcpy(p->data.name, name);

p->data.score = score;

p->next = NULL;

NODE *prev = NULL;

NODE *ptr = *startp;

NODE *np = startp;

while (np != NULL) {

if(strcmp(ptr->data.name, name) >= 0)

break;

prev = ptr;

ptr = ptr->next;

}

if(prev == NULL) {

*startp = p;

p->next = ptr;

} else {

prev->next = p;

p->next = ptr;

}

}

int delete(NODE **startp, char *name) {

NODE *ptr = *startp;

if (ptr != NULL) {

*startp = ptr->next;

free(ptr);

}

}

void clean(NODE **startp) {

struct node *temp, *np = *startp;

while (np != NULL) {

temp = np;

np = np -> next;

free(temp);

}

*startp = NULL;

}

// the following functions are adapted and modified from previous assignments. You make use of them.

void report_data(NODE *start, char *filename) {

NODE *np = start;

int count = 0;

float mean = 0;

float stddev = 0;

int histogram[6] = {0};

FILE *fp = fopen(filename, "w");

fprintf(fp, "grade report ");

while (np != NULL) {

count++;

mean += np->data.score;

stddev += np->data.score * np->data.score ;

//histogram data

if (np->data.score >=100) histogram[0]++;

else if (np->data.score < 50) histogram[5]++;

else histogram[(unsigned int) (99.99-np->data.score)/10]++;

fprintf(fp, "%-15s%3.1f%4c ", np->data.name, np->data.score, letter_grade(np->data.score));

np = np->next;

}

mean /= count;

stddev = sqrt(stddev/count - mean*mean);

fprintf(fp, " statistics summary ");

fprintf(fp, "%-15s%d ", "count", count);

fprintf(fp, "%-15s%3.1f ", "mean", mean);

fprintf(fp, "%-15s%3.1f ", "stddev", stddev);

fprintf(fp, "%-15s%3.1f ", "median", median(start));

fprintf(fp, "histogram ");

int i;

fprintf(fp, "%-15s%d ", "[90,100]", histogram[0]);

for (i=1; i<5; i++) {

fprintf(fp, "[%d,%d) %d ", 90-i*10, 100-i*10, histogram[i]);

}

fprintf(fp, "%-15s%d ", "[0,50)", histogram[5]);

fclose(fp);

}

void import_data(NODE **startp, char *filename) {

char line[40], name[20];

FILE *fp = fopen(filename, "r");

char *result = NULL;

char delimiters[] = ",";

float score = 0;

if (fp == NULL) {

perror("Error while opening the file. ");

exit(EXIT_FAILURE);

}

while (fgets(line, sizeof(line), fp) != NULL) {

result = strtok(line, delimiters);

strcpy(name, result);

result = strtok(NULL, delimiters);

score = atof(result);

insert(startp, name, score);

}

fclose(fp);

}

char letter_grade(float s){

char r = 'F';

if (s >= 85) r = 'A';

else if (s >= 70) r = 'B';

else if (s >= 60) r = 'C';

else if (s >= 50) r = 'D';

else r = 'F';

return r;

}

void swap(float *first, float *second )

{

float temp = *first;

*first = *second;

*second = temp;

}

void quick_sort(float *a, int left, int right)

{

float key;

int i,j;

if( left < right ) {

key = *(a+left);

i = left+1;

j = right;

while(i <= j) {

while( i <= right && *(a+i) <= key) i++;

while( j >= left && *(a+j) > key ) j--;

if( i < j) swap(a+i, a+j);

}

swap(a+left, a+j);

quick_sort(a, left, j-1);

quick_sort(a, j+1, right);

}

}

float median(NODE *start)

{

if (start == NULL) return 0;

int len = 0, i=0;

NODE *np = start;

while (np) { len++; np = np->next; }

float a[len];

for (i=0, np=start; inext) {

a[i] = np->data.score;

}

quick_sort(a, 0, len-1);

return (len % 2 == 1)? a[len/2] : (a[len/2-1] + a[len/2])/2 ;

}

assignment

1. Define singly linked list node structure NODE to hold RECORD data.
2. void display(NODE *start); this displays the RECORD data in the linked list.
3. NODE *search(NODE *start, char *name); this searches the linked list by the name data.
4. void insert(node **startp, char *name, float score); this inserts a record into the linked list at position of dictionary (lexicographical) order of the data.name.
5. int delete(NODE **startp, char *name); this deletes a node with RECORD data of the name from the linked list and returns 1 if successful or 0 otherwise.
6. void clean(NODE **startp); this cleans the linked list, namely free all nodes.

record_llist.h

#ifndef RECORD_LLIST

#define RECORD_LLIST

#include

#include

#include

#include

/**

* RECORD structure

* name - char array for person's name

* score - float score of record

*/

typedef struct record{

char name[40];

float score;

} RECORD;

/**

* linked list node structure

* data - RECORD data

* next - pointer pointing to next node of linked list

*/

typedef struct node {

int data;

struct node *next;

} NODE;

/**

* Display linked list.

* @param start Pointer to the first node of linked list.

*/

void display(NODE *start);

/**

* Search linked list for name key.

* @param start Pointer to the first node of linked list.

* @param name Key to search

* @return Pointer to found node if found; otherwise NULL

*/

NODE *search(NODE *start, char *name);

/**

* Insert new record to linked list at the sorted position.

* @param startp Pointer pointing to the start pointer of linked list, used to update the start node address in case of change.

* @param name The name data of new record.

* @param score The score data of new record

*/

void insert(NODE **startp, char *name, float score);

/**

* your comment

*/

int delete(NODE **startp, char *name);

/**

* your comment

*/

void clean(NODE **startp);

// The following functions are adapted and/or modified from previous assignment

void import_data(NODE **startp, char *filename);

void report_data(NODE *start, char *filename);

char letter_grade(float score);

void swap(float *first, float *second );

void quick_sort(float *a, int left, int right);

float median(NODE *start);

#endif