/*Program that utilizes a structure and linked list to store*/
/*employee information taken from the keyboard*/
/*Programmer:  Class: C*/
/*Instructor:   Date: April 23rd, 2007*/
/*Language: C (gcc target)

#include <stdio.h>    /*Library to be included*/
#include <stdlib.h>   /*Library to be included*/
#include <string.h>   /*Library to be included */
#define NO_EMPLOYEES 3/* Number of employees entered */
#define MAXLENGTH 21 /* the maximum length of the names */

/*Define Structure for employee*/
typedef struct employee
{
    char firstname[MAXLENGTH];/*Max length of first name*/
    char lastname[MAXLENGTH];/*Max length of last name*/
    int id; /*ID declared as int*/
    struct employee *next; 
}
empl;

empl* insert(empl *first, empl *new);

*/Main declared*/

int main(int argc, char **argv)
{
    empl *head, *temp;
    int i;
    head=NULL;

 */ Information will be entered here using keyboard*/
 */ It will loop 3 times */   
    for(i=0; i<NO_EMPLOYEES; i++){
        temp = (empl*)calloc(1, sizeof(empl));
    
        printf("Please enter the first name, the last name and the user id:\n");
        scanf("%s %s %d", temp->firstname, temp->lastname, &temp->id);
        temp->next = NULL;
        head = insert(head, temp);
    }
/* All data will printed out here that was entered*/
/*Lowest to highest ID number*/
    printf("The employee with the lowest id number is\n");
    printf("First name: %s\n", head->firstname);
    printf("Last name: %s\n", head->lastname);
    printf("User ID: %d\n", head->id);
    
    temp = head;
    printf("Here's a list with all employees\n\n");
    while(temp != NULL){
        printf("First name: %s\n", temp->firstname);
        printf("Last name: %s\n", temp->lastname);
        printf("User ID: %d\n", temp->id);
        temp = temp->next;
    }

    return 0;
}

empl* insert(empl *first, empl *new)
{
    empl *cur, *prev;
    /* return the new node if it's the first node */
    if(first == NULL)
{
        return new;
    }
    cur = first;
    prev = first;

    /* loop until we have no next node anymore */
    while(cur != NULL)
{
        /* see if our current node has a heigher number than the number we're looking for */
        if(cur->id < new->id)
{
            prev = cur;
            cur = cur->next;
        }
else
{
            break;
        }
    }
    /* the first node is a special case, so we change that differently */
    if(first==cur)
{
        first = new;
        new->next = cur;
    }
else
{
        prev->next = new;
        new->next = cur;
    }
    
    return first;
}