qsort_example.c

#include <stdio.h>
#include <stdlib.h>

int cmpfloat(const void *n1, const void *n2)
{
  return *( (const float *) n1 ) > *( (const float *) n2 );
}

#define SIZE 3

int main(int argc, char **argv)
{
  float numbers[SIZE];

  printf("Digita os bagulho: ");
  scanf("%f%f%f", &numbers[0], &numbers[1], &numbers[2]);

  qsort(numbers, SIZE, sizeof *numbers, cmpfloat);

  for (int i = 0; i < SIZE; i++)
    printf("%.2f, ", numbers[i]);

  putchar('\n');
  return 0;
}