Sorting an incrementing list in C - c

Question

I am trying to create a list of employees and sort the list based on age each time I add a new employee. The problem I am having is that only a list of 1 employee is "sorted". If I add another employee suddenly all of the ages become 0. Here is my code:
#include <stdio.h>
#include <string.h>
#include "employee.h"
int i = 0;
unsigned int employee_get_num (struct employee* list)
{
unsigned int i;
for (i=0; list[i].name[0]; i++);
return i;
}
void employee_sort (struct employee* list)
{
int n = i;
int I, j;
int tmp;
printf("There are %d employees\n", n);
for(I=0; I<n; I++)
printf("Age: %d\n", list[i-1].age);
for(I=0; I<(n-1); I++)
for(j=0; j<n-I-1; j++)
if(list[j].age > list[j+1].age){
tmp = list[j].age;
list[j].age = list[j+1].age;
list[j+1].age = tmp;
}
printf("Sorted list:\n");
for(I=0; I<n; I++)
printf("%d\n", list[i-1].age); // only printing zeros for some reason
}
void employee_add (struct employee* list)
{
i = i+1; // i is global, keeps track of employees
char first[128];
char last[128];
char space[] = " ";
printf ("First Name: ");
scanf ("%s", first);
printf("Last Name: ");
scanf ("%s", last);
// Concatenate first and last name into one string
strcpy(list[i-1].name, first);
strcat(list[i-1].name, space);
strcat(list[i-1].name, last);
printf (" Age: ");
scanf("%u", &(list->age));
printf ("Wage: ");
scanf("%u", &(list->wage));
employee_sort(&list[i-1]);
}
I think that I might not be increasing correctly.
Header file:
#ifndef _employee_h_
#define _employee_h_
struct employee {
char name[128];
unsigned int age;
unsigned int wage;
};
unsigned int employee_get_num (struct employee* list);
void employee_print (struct employee* e);
void employee_print_all (struct employee* list);
void employee_sort (struct employee* array);
void employee_add (struct employee* list);
void employee_delete (struct employee* list);
#endif
main() (in menu.c)
int main (unsigned int argc, char** argv)
{
struct employee list[MAX];
unsigned int running = 1;
/* Set all bits in the employee array to zero */
memset (list, 0, MAX*sizeof(struct employee));
while (running) {
switch (print_menu()) {
case OPTION_ADD:
employee_add(list);
break;
case OPTION_DEL:
employee_delete(list);
break;
case OPTION_LIST:
employee_print_all(list);
break;
case OPTION_QUIT:
running = 0;
break;
};
}
return 0;
}
I left out the rest of menu.c because it only prints the menu which you'll see below.
The output should look like:
[1] Add New Employee
[2] Delete an Employee
[3] List All by Age (Acending)
[4] Quit
------------------------
Selection: 1
First Name: Bob
Last Name: Smith
Age: 40
Wage: 60000
There are 1 employees
Age: 40
Sorted list:
40
[1] Add New Employee
[2] Delete an Employee
[3] List All by Age (Acending)
[4] Quit
------------------------
Selection: 1
First Name: John
Last Name: Connor
Age: 35
Wage: 62000
There are 2 employees
Age: 40
Age: 35
Sorted list:
35
40
I added some extra print statements just to show what it is supposed to be doing.
I'm also worried that it is only going to sort the age and not the rest of the information

Answer 1

Firstly in employee_add when calling employee_sort you are passing the last struct element. Pass the first employee. Change last line in employee_add to
employee_sort(list);
Next problem
If I add another employee suddenly all of the ages become 0
No it doesn't. In employee_sort in the for loop before sorting, change it to
printf("There are %d employees\n", n);
for(I=0; I<n; I++)
printf("Age: %d\n", list[I].age);
Next
While taking age and wage input change it to
scanf("%u", &(list[i-1].age));
scanf("%u", &(list[i-1].wage));
I'm also worried that it is only going to sort the age and not the rest of the information
Yes you are only sorting age, you should sort whole struct based on age.
for(I=0; I<(n-1); I++)
for(j=0; j<n-I-1; j++)
if(list[j].age > list[j+1].age){
tmp = list[j];
list[j] = list[j+1];
list[j+1] = tmp;
}
And the final problem of printing sorted list
printf("Sorted list:\n");
for(I=0; I<n; I++)
printf("%d\n", list[I].age);
PS Note the list[I] in every printf and not list[i+1]
Edit
Instead of sorting it yourself, you can use qsort biult in function in stdlib.h header file.
Implementation: You will need to define a comparator function as you dont have a traditional array to sort
Just define a function
int comparator(const struct employee *p, const struct employee *q)
{
int l = p->age;
int r = q->age;
return (l - r);
}
And then where you sort the list call qsort like this
qsort(list,i,sizeof(list[0]),comparator);