qsort using function pointers in c lang

Implement qsort using function pointers

#include 

#include 

#include 

#include 

struct s

{

    char empname[5];

    int empid;

};

int int_call(const void *a1,const void *b1)

{

    const int *a = (const int *)a1;

    const int *b = (const int *)b1;

    if (*a > *b)

        return 1;

    else

    {

        if (*a == *b) 

            return 0;

        else

            return -1;

    }

}

int string_call(const void *a1, const void *b1)

{

    const char *a = (const char *)a1;

    const char *b = (const char *)b1;

    return(strcmp(a, b));

}

void main()

{

    int array1[5]={20, 30, 50, 60, 10};

    struct s emprec[5];

    int i, j;

    strcpy(emprec[0].empname, "bbb");

    emprec[0].empid = 100;

    strcpy(emprec[1].empname, "ccc");

    emprec[1].empid = 200;

    strcpy(emprec[2].empname, "eee");

    emprec[2].empid = 300;

    strcpy(emprec[3].empname, "aaa");

    emprec[3].empid = 400;

    strcpy(emprec[4].empname,"ddd");

    emprec[4].empid = 500;

    qsort(array1, 5, sizeof(int), int_call);

    qsort(emprec, 5, sizeof(struct s), string_call);

    for (i = 0; i < 5; i++)

        printf("%d\t", array1[i]);

    printf("\nSorting of Structure elements ");

    for (i = 0; i < 5; i++)

        printf("\n%s\t%d", emprec[i].empname, emprec[i].empid);

    printf("\n");

 getch();

}

Output

10    20    30    50    60    

Sorting of Structure elements 

aaa    400

bbb    100

ccc    200

ddd    500

eee    300

Implement Pigeonhole Sort

#include 

#include 

#define max 7

void pigeonhole_sort(int, int, int *);

void main()

{

    int a[max], i, min, max;

    printf("enter the values into the matrix :");

    for (i = 0; i < max; i++)

    {

        scanf("%d", &a[i]);

    }

    min = a[0];

    max = a[0];

    for (i = 1; i < max; i++)

    {

        if (a[i] < min)

        {

            min = a[i];

        }

        if (a[i] > max)

        {

            max = a[i];

        }

    }

    pigeonhole_sort(min, max, a);

    printf("Sorted order is :\n");

    for (i = 0; i < max; i++)

    {

        printf("%d", a[i]);

    }

}

void pigeonhole_sort(int mi, int ma, int * a)

{

    int size, count = 0, i;

    int *current;

    current = a;

    size = ma - mi + 1;

    int holes[size];

    for (i = 0; i < size; i++)

    {

        holes[i] = 0;

    }

    for (i = 0; i < size; i++, current++)

    {

        holes[*current-mi] += 1;

    }

    for (count = 0, current = &a[0]; count < size; count++)

    {

        while (holes[count]--> 0)

        {

            *current++ = count + mi;

        }

    }

}

Output

enter the values into the matrix :7 3 8 2 5 4 9

Sorted order is :

2345789

enter the values into the matrix :1 2 3 4 5 6 7

Sorted order is :

1234567

enter the values into the matrix :7 6 5 4 3 2 1

Sorted order is :

1234567