BigUnsigned operator+(const BigUnsigned& one) const {
BigUnsigned res;
for (int i = 0, x = 0; i < max(len, one.len) + 1; i++) {
int tmp = d[i] + one.d[i] + x;
res.d[res.len++] = tmp % 10;
x = tmp / 10;
}
res.Clean();
return res;
}
BigUnsigned operator*(const BigUnsigned& one) {
BigUnsigned res;
res.len = len + one.len;
for(int i = 0; i < len; i++)
for(int j = 0; j < one.len; j++)
res.d[i + j] += d[i] * one.d[j];
for(int i = 0; i < res.len - 1; i++) {
res.d[i + 1] += res.d[i] / 10;
res.d[i] %= 10;
}
res.Clean();
return res;
}
