void Bigint::multiply(const Bigint& number)
{
Bigint mulResult;
std::string mstring;
std::vector<int> mparts;
std::string fnvalue = toString();
std::string snvalue = number.toString();
if(fnvalue.length()>snvalue.length())
{
if(!number.isPositive)
mstring = snvalue.substr(1);
else
mstring = snvalue;
mparts = parts;
}
else
{
if(!number.isPositive)
mstring = fnvalue.substr(1);
else
mstring = fnvalue;
mparts = number.parts;
}
if(mstring!="" && mparts.size()>0)
{
int position = 0;
for (int i = mstring.length(); i > 0 ; i--, position++) {
std::string numstr = BLANK;
int mult = mstring.at(i-1) - '0';
int carryOver = 0;
for (int j=0;j<(int)mparts.size();j++) {
std::string res = CastUtil::lexical_cast<std::string>(mparts.at(j)*mult);
if(j!=(int)mparts.size()-1)
{
std::string mrtn = CastUtil::lexical_cast<std::string>(mparts.at(j));
if(res.length()>mrtn.length())
{
int numm = CastUtil::lexical_cast<int>(res.substr(1)) + carryOver;
numstr = CastUtil::lexical_cast<std::string>(numm) + numstr;
carryOver = res.at(0) - '0';
}
else
{
int numm = CastUtil::lexical_cast<int>(res) + carryOver;
numstr = CastUtil::lexical_cast<std::string>(numm) + numstr;
carryOver = 0;
}
if(j==0)
{
int nl = numstr.length();
for (int jj = 0; jj < NUM_LENGTH-nl; jj++) {
numstr = ZERO + numstr;
}
}
}
else
{
int numm = CastUtil::lexical_cast<int>(res) + carryOver;
numstr = CastUtil::lexical_cast<std::string>(numm) + numstr;
carryOver = 0;
}
}
for (int j = 0; j < position; j++) {
numstr += ZERO;
}
try {
Bigint num(numstr);
mulResult.internalAdd(num);
} catch (...) {
}
}
}
this->parts = mulResult.parts;
if(isPositive!=number.isPositive)
{
isPositive = false;
}
else if(isPositive==number.isPositive)
{
isPositive = true;
}
}
