// false == left > right, true == left < right
int bigint::do_bigless(const bigvalue_t& left, const bigvalue_t& right) {
auto left_it = left.rbegin();
auto right_it = right.rbegin();
auto left_end = left.rend();
auto right_end = right.rend();
//cout << "left size" << left.size() << endl;
//cout << "right size" << right.size() << endl;
if(left.size() > right.size()) {
return -1;
}
if(left.size() < right.size()) {
return 1;
}
while(left_it != left_end and right_it != right_end) {
if(*left_it > *right_it) {
return -1;
}
else if (*left_it < *right_it) {
return 1;
}
++left_it;
++right_it;
}
return 0;
}
bool bigint::do_bigabs_less (const bigvalue_t& left, const bigvalue_t& right) {
if(right.size() > left.size()) {
return true;
}
bigvalue_t::const_reverse_iterator left_it = left.rbegin();
bigvalue_t::const_reverse_iterator right_it = right.rbegin();
bigvalue_t::const_reverse_iterator left_end = left.rend();
bigvalue_t::const_reverse_iterator right_end = right.rend();
while(left_it != left_end and right_it != right_end) {
if(*left_it > *right_it) {
return false;
}
else if (*left_it < *right_it) {
return true;
}
++left_it;
++right_it;
}
return false;
}
bigint::bigvalue_t bigint::do_bigadd(const bigvalue_t& left, const bigvalue_t& right) {
bigvalue_t sum;
int carry = 0;
bool left_empty = false;
bool right_empty = false;
bigvalue_t::const_reverse_iterator left_it = left.rbegin();
bigvalue_t::const_reverse_iterator right_it = right.rbegin();
bigvalue_t::const_reverse_iterator left_end = left.rend();
bigvalue_t::const_reverse_iterator right_end = right.rend();
if(left.size() == 0) {
left_empty = true;
}
if(right.size() == 0) {
right_empty = true;
}
while(true) {
int curr_value = (left_empty?0:*left_it) + (right_empty?0:*right_it) + carry;
carry = 0;
if(curr_value >= 10) {
carry = 1;
curr_value -= 10;
}
sum.push_back(curr_value);
if(++left_it == left_end) {
left_empty = true;
}
if(++right_it == right_end) {
right_empty = true;
}
if(left_empty and right_empty) {
if(carry == 1) {
sum.push_back(carry);
}
break;
}
}
return sum;
}
// false == left > right true == left < right
int bigint::do_bigless(const bigvalue_t& left, const bigvalue_t& right) {
bigvalue_t::const_reverse_iterator left_it = left.rbegin();
bigvalue_t::const_reverse_iterator right_it = right.rbegin();
bigvalue_t::const_reverse_iterator left_end = left.rend();
bigvalue_t::const_reverse_iterator right_end = right.rend();
if(left.size() > right.size()) {
return -1;
}
if(left.size() < right.size()) {
return 1;
}
while(left_it != left_end and right_it != right_end) {
if(*left_it > *right_it) {
return -1;
}
else if (*left_it < *right_it) {
return 1;
}
++left_it;
++right_it;
}
return 0;
}
bigint::bigvalue_t bigint::do_bigsub(const bigvalue_t& left, const bigvalue_t& right) {
bigvalue_t sum;
int carry = 0;
bool left_empty = false;
bool right_empty = false;
bigvalue_t::const_reverse_iterator left_it = left.rbegin();
bigvalue_t::const_reverse_iterator right_it = right.rbegin();
bigvalue_t::const_reverse_iterator left_end = left.rend();
bigvalue_t::const_reverse_iterator right_end = right.rend();
if(left.size() == 0) {
left_empty = true;
}
if(right.size() == 0) {
right_empty = true;
}
while(true) {
int curr_value = (left_empty?0:*left_it) - (right_empty?0:*right_it) + carry;
carry = 0;
if(curr_value < 0 and !left_empty) {
carry = -1;
curr_value += 10;
}
sum.push_back(curr_value);
if(++left_it == left_end) {
left_empty = true;
}
if(++right_it == right_end) {
right_empty = true;
}
if(left_empty and right_empty) {
break;
}
}
//remove leading 0s
//sum = trim(sum);
return sum;
}