bsearch- bez struct, działa

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

int compareByString(const void* key, const void* element);

int compareByInt(const void* key, const void* element);

int compereDouble(const void *key, const void *element);

void *bsearch(const void *key, const void *base, size_t nmemb, size_t size, int (*compare)(const void *, const void *))
{
      const void* currentElement = 0;
    int start = 0;
    int end = nmemb;
    int middle;
    int searchElement;

    while (start <= end)
    {
        middle = start + (end - start) / 2;
        currentElement = (char*)base + middle* size;
        searchElement = (*compare)(key, currentElement);

        if (searchElement == 0)
        {
            return ((void*)currentElement);
        }
        else if (searchElement < 0)
        {
            end = middle - 1;
        }
        else
        {
            start = middle + 1;
        }
    }

    return NULL;
}


int main (int argc, char *argv[])
{

    double *foundDouble = NULL;
    double array[10] = {1.454, 2.2, 3.1343333, 4.34322, 5.4324, 6.7669, 7.9999};
    double searchedDouble = 3.1343333;
    foundDouble = (double*)bsearch(&searchedDouble, array, sizeof(array)/sizeof(double), sizeof(double), compereDouble);
    if (foundDouble == NULL)
    {
        printf("Value not found\n");
    } else {
        printf("found value %f\n", *foundDouble);
    }
    int searchedValue = 3;
    int *foundInt = NULL;
    int arrayInt[10] = {1, 2, 3, 4, 5, 6, 7, 8};
    foundInt = (int*)bsearch(&searchedValue, arrayInt, sizeof(arrayInt)/sizeof(int), sizeof(int), compareByInt);
    if (foundInt == NULL)
    {
        printf("Value not found\n");
    } else {
        printf("found value %d\n", *foundInt);
    }

  return 0;
}

int compareByString(const void* key, const void* element)
{
    return strcmp((char *)key, (char *)element);
}


int compareByInt(const void* key, const void* element)
{
    return (*(unsigned char *)key - *(unsigned  char *)element);
}

int compereDouble(const void *key, const void *element)
{
    return (*(double*)key - *(double*)element);

}