LongInt LongInt::operator-( const LongInt &rhs ) const {
LongInt result;
if(negative == rhs.negative) {
if ((*this) <= rhs && !negative) {
LongInt subtrahend(rhs);
subtrahend.convertSign();
subtrahend.negative = 0;
result = (*this)+subtrahend;
result.negative = 1;
} else if ((*this) > rhs && !negative) {
LongInt minuend((*this));
minuend.convertSign();
minuend.negative = 0;
result = minuend+rhs;
result.negative = 1;
result.convertSign();
} else if ((*this) <= rhs && negative) {
LongInt minuend((*this));
minuend.negative = 0;
LongInt subtrahend(rhs);
subtrahend.convertSign();
result = minuend+subtrahend;
result.negative = 1;
} else {
LongInt minuend((*this));
minuend.convertSign();
LongInt subtrahend(rhs);
subtrahend.negative = 0;
result = minuend+subtrahend;
result.negative = 1;
result.convertSign();
}
result.remove0s();
} else {
if (negative && !rhs.negative){
LongInt temp(rhs);
temp.convertSign();
result = (*this) + (temp);
}
if (!negative && rhs.negative) {
LongInt temp(rhs);
temp.convertSign();
result = (*this) +(temp);
}
}
return result;
}
// Arithmetic binary operators
LongInt LongInt::operator+( const LongInt &rhs ) const {
LongInt result;
if(negative == rhs.negative) {
if (negative) {
LongInt left(*this);
LongInt right(rhs);
left.convertSign();
right.convertSign();
result = left + right;
result.convertSign();
return result;
}
Deque<char> r(rhs.digits); //right side
Deque<char> l(digits); //left side
int i = 0;
int carry = 0;
while (i < max(r.size(), l.size())) {
int sum;
int lval;
int rval;
(!l.isEmpty()) ? lval = (int)l.removeBack() - 48 : lval = 0;
(!r.isEmpty()) ? rval = (int)r.removeBack() - 48 : rval = 0;
sum = lval + rval + carry;
carry = sum / 10;
result.digits.addFront((char)(sum % 10 + 48));
}
if (carry)
result.digits.addFront('1');
} else {
if (rhs.negative) { // this positive rhs negative
LongInt temp(rhs);
temp.convertSign();
result = operator-(temp);
} else { // this negative rhs positive
LongInt temp((*this));
temp.convertSign();
result = rhs.operator-(temp);
}
}
return result;
}
