sprintf char*

bool is_integer_eps(float k, float eps)
{
    return k - floor(k) < eps;
}
void reverse_substr(char* &str,int start,int end)
{
    int i, j;
    for (i = start, j = end; i < j; i++, j--)
    {
        char temp = str[i];
        str[i] = str[j];
        str[j] = temp;
    }
}

char* native_sprintf(float k)
{
    char* str = new char[100];
    int iter = 0;
    //sprintf(str, "%f", k);
    int data1 = (int)k,data2; //целая часть числа
    float data2f = k - data1; //дробная часть числа
    while(!is_integer_eps(data2f,0.001))
        data2f *= 10;
    data2 = (int)data2f;
    while(data1>0)
    {
        str[iter] = data1%10 + '0';
        data1 /= 10;
        iter++;
    }
    reverse_substr(str,0,iter-1);
    str[iter] = '.';
    iter++;
    int iter_point = iter;
    while(data2>0)
    {
        str[iter] = data2%10 + '0';
        data2 /= 10;
        iter++;
    }
    reverse_substr(str,iter_point,iter-1);
    str[iter] = '\0';
    return str;
}

void PrintStr(char* str)
{
    for(int i=0;i<sizeof(str);i++)
        cout<<str[i];
}