Nombre aléatoires c++

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

#define USING "a.out <elements count> <lower born> <upper born>\n" 
#define COUNT_ERROR "Error : count must be greater than zero.\n" 
#define BORN_ERROR "Error : the lower born must be lesser than the upper born.\n" 
#define RANGE_ERROR "Error : the elements count must be lesser than the rand range.\n" 

unsigned long ulong_rnd() 
{ 
    unsigned char bytes[4] = {rand(), rand(), rand(), rand()}; 

    unsigned long returnValue = 0; 
    returnValue  |= bytes[0] << 24; 
    returnValue  |= bytes[1] << 16; 
    returnValue  |= bytes[2] << 8; 
    returnValue  |= bytes[3] << 0; 

    return returnValue; 
} 

int ulong_rnd_fill(unsigned long *pOut, long count, unsigned long min, unsigned long max) 
{ 
    if (max < min) return -1; 

    unsigned long mod = max - min + 1, lngtmp; 

    if (mod < count) return -2; 

    unsigned long *pSort = (unsigned long*) malloc(sizeof(unsigned long) * count); 

    if (!pSort) return -4; 

    long i, ii; 
    for (i=0; i<count; i++) 
    { 
        pSort[i] = ulong_rnd() % mod + min; 
        for (ii=0; pSort[i]>=pSort[ii] && ii<i; ii++, pSort[i]++); 
        pOut[i] = pSort[i]; 
        for (;ii<i; ii++) 
        { 
            lngtmp = pSort[ii]; 
            pSort[ii] = pSort[i]; 
            pSort[i] = lngtmp; 
        } 

        mod --; 
    } 

    return 0; 
} 

void printArrayLng(long *pIn, int size, const char* array_name) 
{ 
    int i; 
    for(i=0; i<size; i++) printf("%s[%d] = %ld\n", array_name, i, pIn[i]);; 
} 
int main(int argc, char *argv[]) 
{ 
    if (argc != 4) 
    { 
        printf(USING); 
        return -1; 
    } 

    long elem_count = atol(argv[1]), 
         lowerBorn  = atol(argv[2]), 
         upperBorn  = atol(argv[3]); 
    if (elem_count < 0) 
    { 
        printf(COUNT_ERROR); 
        return -1; 
    } 

    if (lowerBorn > upperBorn) 
    { 
        printf(BORN_ERROR); 
        return -1; 
    } 

    if (upperBorn - lowerBorn + 1 < elem_count) 
    { 
        printf(RANGE_ERROR); 
        return -1; 
    } 

    srand(time(NULL)); 
    long *rnd_array = (long*) malloc(sizeof(unsigned long) * elem_count); 

    ulong_rnd_fill((unsigned long*)rnd_array, elem_count, 0, upperBorn - lowerBorn); 

    long i; 
    for (i=0; i<elem_count; i++) rnd_array[i] = ((unsigned long)rnd_array[i]) + lowerBorn; 
    printArrayLng(rnd_array, elem_count, "random"); 

    return 0; 
}