Submission #490552

#	Time	Username	Problem	Language	Result	Execution time	Memory
490552		Rainbowbunny	Palindrome-Free Numbers (BOI13_numbers)	C++17	100 / 100	1 ms	344 KiB

numbers

#include <bits/stdc++.h>
using namespace std;

vector <int> Digit;
long long dp[20][2][2][11][11];

long long l, r;

long long F(int pos, int big, int start, int ppdigit, int pdigit)
{

    if(pos == (int)Digit.size())
    {
        return 1;
    }
    long long &cur = dp[pos][big][start][ppdigit][pdigit];
    if(cur != -1)
    {
        return cur;
    }
    cur = 0;
    int can = (big ? 9 : Digit[pos]);
    for(int nxtdigit = 0; nxtdigit <= can; nxtdigit++)
    {
        if(nxtdigit == pdigit or nxtdigit == ppdigit)
        {
            continue;
        }
        cur += F(pos + 1, big | (nxtdigit < Digit[pos]), start | (nxtdigit > 0), pdigit, (start | (nxtdigit > 0)) ? nxtdigit : 10);
    }
    return cur;
}

long long Count(long long x)
{
    if(x < 0)
    {
        return 0;
    }
    for(int i = 0; i < 20; i++)
    {
        for(int j = 0; j < 2; j++)
        {
            for(int k = 0; k < 2; k++)
            {
                for(int l = 0; l < 11; l++)
                {
                    for(int h = 0; h < 11; h++)
                    {
                        dp[i][j][k][l][h] = -1;
                    }
                }
            }
        }
    }
    Digit.clear();
    while(x)
    {
        Digit.push_back(x % 10);
        x /= 10;
    }
    reverse(Digit.begin(), Digit.end());
    return F(0, 0, 0, 10, 10);
}

int main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);
    cin >> l >> r;
    cout << Count(r) - Count(l - 1) << '\n';
}

• Subtask 1: 25 / 25
• Subtask 2: 75 / 75