LongInt LongInt::longMult(LongInt& otherLongInt) {
LongInt theAnswer = LongInt(0);
if (!this->eqZero() && !otherLongInt.eqZero()) {
int thisSize = (int) this->myLongInt.size();
int otherSize = (int) otherLongInt.myLongInt.size();
LongInt multTemp;
bool isMultTempValued = false;
for (int j = 0; j < otherSize; j++) { // j is the iterator through otherLongInt
long long mult2 = otherLongInt.myLongInt[j];
multTemp.setZero_();
for (int k = 0; k <= j-1; k++) {
multTemp.myLongInt.push_back(0);
}
for (int i = 0; i < thisSize; i++) { // i is the iterator through this
long long mult1 = this->myLongInt[i];
long long multResult = mult1 * mult2;
// There might be overflow from the previous multiplication
multResult += multTemp.myLongInt[j+i];
if (!isMultTempValued && (multResult > 0)) isMultTempValued = true;
// We check for overflow
long exceed = multResult / DIVISOR;
if (exceed > 0) multResult %= DIVISOR; // If overflow take remainder
multTemp.myLongInt[j+i] = (long) multResult;
if ((i != thisSize-1) || (exceed > 0))
multTemp.myLongInt.push_back(exceed);
}
if (isMultTempValued) multTemp.signType = type_positive;
theAnswer = theAnswer + multTemp;
}
}
return theAnswer;
}
LongInt LongInt::minusHelper(LongInt& newNumber) {
long carryover = 0L;
LongInt theAnswer;
theAnswer.signType = type_positive;
int i;
long resultant;
if (myLongInt.size() == newNumber.myLongInt.size()){
if (*this > newNumber){
for (i = 0; i < newNumber.myLongInt.size(); i++){
if (myLongInt[i] >= (newNumber.myLongInt[i] + carryover)) {
resultant = myLongInt[i] - newNumber.myLongInt[i] - carryover;
carryover = 0L;
} else {
resultant = DIVISOR + myLongInt[i] - newNumber.myLongInt[i] - carryover;
carryover = 1L;
}
theAnswer.myLongInt.push_back(resultant);
}
} else {
for (i = 0; i < newNumber.myLongInt.size(); i++){
if (newNumber.myLongInt[i] >= (myLongInt[i] + carryover)) {
resultant = newNumber.myLongInt[i] - myLongInt[i] - carryover;
carryover = 0L;
} else {
resultant = DIVISOR + newNumber.myLongInt[i] - myLongInt[i] - carryover;
carryover = 1L;
}
theAnswer.myLongInt.push_back(resultant);
}
theAnswer.signType = type_negative;
}
} else if (myLongInt.size() > newNumber.myLongInt.size()){
for (i = 0; i < newNumber.myLongInt.size(); i++){
if (myLongInt[i] >= (newNumber.myLongInt[i] + carryover)) {
resultant = myLongInt[i] - newNumber.myLongInt[i] - carryover;
carryover = 0L;
} else {
resultant = DIVISOR + myLongInt[i] - newNumber.myLongInt[i] - carryover;
carryover = 1L;
}
theAnswer.myLongInt.push_back(resultant);
}
for (int j = i; j < myLongInt.size(); j++){
if (carryover == 1L && myLongInt[j] == 0L) {
resultant = DIVISOR - carryover;
carryover = 1L;
} else {
resultant = myLongInt[j] - carryover;
carryover = 0L;
}
theAnswer.myLongInt.push_back(resultant);
}
} else {
for (i = 0; i < myLongInt.size(); i++){
if (newNumber.myLongInt[i] >= (myLongInt[i] + carryover)) {
resultant = newNumber.myLongInt[i] - myLongInt[i] - carryover;
carryover = 0L;
} else {
resultant = DIVISOR + newNumber.myLongInt[i] - myLongInt[i] - carryover;
carryover = 1L;
}
theAnswer.myLongInt.push_back(resultant);
}
for (int j = i; j < newNumber.myLongInt.size(); j++){
if (carryover == 1L && newNumber.myLongInt[j] == 0L) {
resultant = DIVISOR - carryover;
carryover = 1L;
} else {
resultant = newNumber.myLongInt[j] - carryover;
carryover = 0L;
}
theAnswer.myLongInt.push_back(resultant);
}
theAnswer.signType = type_negative;
}
// removing zeros
bool zero = true;
for (int k = (theAnswer.myLongInt.size() - 1); k >= 0 && zero; k--) {
if (theAnswer.myLongInt[k] != 0L) {
zero = false;
} else {
theAnswer.myLongInt.erase(theAnswer.myLongInt.end() - 1);
}
}
if (zero) {
theAnswer.setZero_();
}
return theAnswer;
}
