#ifndef _STUDENTS
#define _STUDENTS  1

#define ADD    "ADD"
#define DEL    "DEL"
#define RPN    "RPN"
#define RBS    "RBS"
#define GRADE  "GRADE"
#define RSG    "RSG"
#define RAS    "RAS"

#define MAX_OPCODES 7

#define C_ADD   0
#define C_DEL   1
#define C_RPN   2
#define C_RBS   3
#define C_GRADE 4
#define C_RSG   5
#define C_RAS   6

#define NOT_FOUND -1

#define MAX_STRING 100
#define TABLE_SIZE 20

typedef struct string {
	char *string;
	int len;
} STRING;

typedef struct course {
        STRING *coursenum;
        STRING *title;
        char   grade;
        struct course *next;
} COURSE;

typedef struct userdat {
	STRING *real_name_first;
	STRING *real_name_last;
        STRING *address;
        STRING *city;
        STRING *state;
        STRING *zip;
        STRING *ssn;
        COURSE *classes;
} USERDAT;

typedef struct hashnode {
	STRING *key;
	USERDAT *data;
	struct hashnode *next;
} HASHNODE;

typedef struct hash_table {
	int size;
	HASHNODE **table;
} HASH_TABLE;

void add_user_func(FILE *fin);
void del_user_func(FILE *fin);
void rpn_func(FILE *fin);
void rbs_func(FILE *fin);
void grade_func(FILE *fin);
void rsg_func(FILE *fin);
COURSE *make_course();
USERDAT *add_user(FILE *fin);
USERDAT *make_userdat();
STRING *make_string();
void add_string(STRING *strng, char *s);
void print_user(USERDAT *user);
HASHNODE *make_node(USERDAT *new_data, HASHNODE *next, STRING *key);
HASHNODE *find_prev_node(char *data);
void print_node(HASHNODE *node);
void print_all();
void add_node(USERDAT *new_user);
HASHNODE *find_by_name(char *first, char *last);
HASHNODE *find_by_ssn(char *ssn);
void end_prog();
void free_node(HASHNODE *node);
void free_user(USERDAT *data);
void free_courses(COURSE *class);
void free_string(STRING *s);
HASH_TABLE *make_hash(int size);
int hash_key(int key, int size);
int hash_index(char *key,int size);
void clear_hash();
int s_code(char *string);
char *rm_newline(char *string);
char *str_dup(char *string);
void del_by_ssn(char *ssn);

#endif