# | Time | Username | Problem | Language | Result | Execution time | Memory |
---|---|---|---|---|---|---|---|
520049 | blue | Palindrome-Free Numbers (BOI13_numbers) | C++17 | 0 ms | 0 KiB |
This submission is migrated from previous version of oj.uz, which used different machine for grading. This submission may have different result if resubmitted.
#include <iostream>
#include <vector>
using namespace std;
long long pow9[19];
long long count(long long a) //count number of palindrome-free numbers in range [0, a]
{
vector<int> digit;
long long res = 0;
while(a != 0)
{
digit.push_back(a % 10);
a /= 10;
}
int l = digit.size();
if(l == 0)
{
return 1;
}
else if(l == 1)
{
return digit[0] + 1;
}
else if(l == 2)
{
return digit[0] + 10*digit[1] - (digit[1] - (digit[0] < digit[1])); //digit[1] = multiples of 11 below
}
else
{
res += digit[0] + 1 - (digit[1] );
res +=
}
return res;
}
int main()
{
pow9[0] = 1;
for(int i = 1; i < 19; i++) pow9[i] = pow9[i-1] * 9;
long long a, b;
cin >> a >> b;
cout << count(b) - count(a-1) << '\n';
}