#embody <bits/stdc++.h>
utilizing namespace std;
ulong toInt(const vector<int>& digits)
{
ulong n = 0;
for (int i = digits.measurement() - 1; i >= 0; i--)
n = n * 10 + digits[i];
return n;
}
ulong closest_number(ulong N, int D)
{
vector<int> digits;
ulong temp_num = N;
int cur_sum = 0, temp_cur_sum, index;
whereas (temp_num > 0) {
int digit = temp_num % 10;
digits.push_back(digit);
cur_sum += digit;
temp_num /= 10;
}
temp_cur_sum = cur_sum;
if (D == cur_sum)
return N;
else if (D < cur_sum) {
auto n1 = digits;
for (index = 0; cur_sum - D >= n1[index]; index++) {
cur_sum -= n1[index];
n1[index] = 0;
}
n1[index] -= (cur_sum - D);
auto n2 = digits;
cur_sum = temp_cur_sum;
for (index = 0; cur_sum >= D; index++) {
cur_sum -= n2[index];
n2[index] = 0;
}
if (index < n2.measurement())
++n2[index];
else
n2.push_back(1);
++cur_sum;
for (int i = index; i < n2.measurement() && n2[i] > 9;
i++) {
n2[i] = 0;
if (i == n2.measurement() - 1)
n2.push_back(1);
else
++n2[i + 1];
cur_sum -= 9;
}
for (index = 0; D - cur_sum + n2[index] >= 10;
index++) {
cur_sum += (9 - n2[index]);
n2[index] = 9;
}
n2[index] += D - cur_sum;
if (N - toInt(n1) <= toInt(n2) - N)
return toInt(n1);
else
return toInt(n2);
}
else {
auto n1 = digits;
for (index = 0; D - cur_sum + n1[index] >= 10;
index++) {
if (index == n1.measurement())
n1.push_back(0);
cur_sum += (9 - n1[index]);
n1[index] = 9;
}
if (index == n1.measurement())
n1.push_back(0);
n1[index] += D - cur_sum;
auto n2 = digits;
int cur_sum = temp_cur_sum;
for (index = 0; cur_sum < D && index < n2.measurement();
index++) {
cur_sum += (9 - n2[index]);
n2[index] = 9;
}
--n2[index];
--cur_sum;
if (cur_sum < D)
n2.clear();
else {
for (int i = index; i < n2.measurement() && n2[i] < 0;
i++) {
n2[i] = 9;
if (i == n2.measurement() - 1)
n2.pop_back();
else
--n2[i + 1];
cur_sum += 9;
}
for (index = 0; cur_sum - D >= n2[index];
index++) {
cur_sum -= n2[index];
n2[index] = 0;
}
n2[index] = 9 - (cur_sum - D);
}
if (n2.measurement() > 0 && N - toInt(n2) <= toInt(n1) - N)
return toInt(n2);
else
return toInt(n1);
}
}
int major()
{
ulong N = 87220000221835856;
int D = 102;
cout << closest_number(N, D);
return 0;
}
