Нахождение критерия делимости

#include "stdafx.h"
#include "stdlib.h"
#include "string.h"
#include "iostream"
 
class PascalCriterion 
{
    unsigned int Base;
    bool Valid;
    bool Positive;
    unsigned int *Criterion;
    
public:
    PascalCriterion(unsigned int);
    bool Check(char *);
    bool CheckBuff(char *);
    void printCriterion();    
};
 
PascalCriterion::PascalCriterion(unsigned int base)
{
    unsigned int r;
    
    Base = base;
    Criterion = (unsigned int *)malloc(base*sizeof(int));
    Criterion[0] = 1;
    r = 1;
    for (int i = 1; i < base; i++)
    {
        r = (r * 10) % base;
        Criterion[i] = r;
    }
}
 
bool PascalCriterion::Check(char *buffer)
{
    unsigned long srtLength = strlen(buffer) - (Positive ? 1 : 2);
    unsigned long R = 0;
    
    for (unsigned long i = 0; i <= srtLength; i++) 
        R = R + (buffer[srtLength - i + (Positive ? 0 : 1)] - 0x30) * Criterion[i % Base];
    
    return (R % Base == 0 ? true : false);
}
 
bool PascalCriterion::CheckBuff(char *buffer)
{
    unsigned long srtLength = strlen(buffer);
    
    Valid = true;
    Positive = (buffer[0] == '-' ? false : true);
    
    for (unsigned long i = 0; i < srtLength; i++)
    {
        if ((buffer[i] > 0x39 || buffer[i] < 0x30) && !( i == 0 &&  buffer[i] == '-'))
        {
            Valid = false;
            std::cout << "Illegal char '" << buffer[i] << "'\n";
            break;
        }
    }
    return Valid;
}
 
void PascalCriterion::printCriterion()
{
    std::cout << "Base: " << Base << "\n";
    std::cout << "Criterions:";
    for (int i = 0; i < Base; i++) 
        std::cout << (i % 10 == 0 ? "\n": "\t") << Criterion[i];
    std::cout << "\n";    
}
 
 
int main(int argc, char* argv[])
{
    // 2504552993455
    unsigned int base = 293;
    char *buffer;
    PascalCriterion test(base);
    
    buffer = (char *)malloc(1000);
 
test.printCriterion();
 
do
{
std::cout << "Input number: \n";
std::cin >> buffer;
    
if (test.CheckBuff(buffer))
{        
std::cout << "\n" << buffer << "\n";
std::cout << (test.Check(buffer) ? "Can" : "Can't ");
std::cout << " be divided on " << base << "\n";        
}
else
std::cout << "Error in string!\n";
} while (buffer[0] != 'q'); 
return 0;
}