Submission #1121067

#	Time	Username	Problem	Language	Result	Execution time	Memory
1121067		vjudge1	Palindrome-Free Numbers (BOI13_numbers)	C++17	100 / 100	2 ms	508 KiB

numbers

#include <bits/stdc++.h>
#define all(v) v.begin(), v.end()
#define int long long
using namespace std;

const int sz = 20;
int dp[sz][sz][sz][2];
string s;

int f(int ind, int prv, int prv2, bool same)
{
    if(dp[ind][prv][prv2][same] != -1) return dp[ind][prv][prv2][same];
    if(ind == s.size()) return 1;
    int ans = 0;
    for(int i = 0; i <= 9; i++)
    {
        if((i > s[ind] - '0' && same) || i == prv || i == prv2) continue;
        int val = i;
        if(prv == 10 && i == 0) val = 10;
        if(i == s[ind] - '0')
        {
            ans += f(ind + 1, val, prv, same);
        }
        else
        {
            if(same) 
            {
                if(s[ind] - '0' > i) ans += f(ind + 1, val, prv, !same);
            }
            else
            {
                ans += f(ind + 1, val, prv, same);
            }
        }
    }
    return dp[ind][prv][prv2][same] = ans;
}

signed main()
{
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    

    int l, r;
    cin >> l >> r;

    memset(dp, -1, sizeof(dp));
    s = to_string(r);
    r = f(0, 10, 10, 1);

    if(l > 0)
    {
        memset(dp, -1, sizeof(dp));
        s = to_string(l - 1);
        l = f(0, 10, 10, 1);
    }

    cout << r - l;
}  

Compilation message (stderr)

numbers.cpp: In function 'long long int f(long long int, long long int, long long int, bool)':
numbers.cpp:13:12: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   13 |     if(ind == s.size()) return 1;
      |        ~~~~^~~~~~~~~~~

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