Submission #1120329

#	Time	Username	Problem	Language	Result	Execution time	Memory
1120329		vjudge1	Palindrome-Free Numbers (BOI13_numbers)	C++17	72.50 / 100	2 ms	564 KiB

numbers

#include <bits/stdc++.h>

using namespace std;

#define int long long
#define inf 0x3F3F3F3F

int dp[20][11][11][2];

string N;

int f(int i, int a, int b, int ff)
{
  if (i == N.length()) return 1;
  if (dp[i][a][b][ff] != -1) return dp[i][a][b][ff];
  int res = 0;
  for (int c = 0; c <= 9; c++)
  {
    if (a == c || b == c) continue;
    if (ff && c > N[i] - '0') continue;
    int nwf = ff && (c == N[i] - '0');
    res += f(i + 1, b, c, nwf);
  }
  return dp[i][a][b][ff] = res;
}

signed main()
{
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  int a, b;
  cin >> a >> b;
  for (int i = 0; i < 20; i++) for (int j = 0; j < 11; j++) for (int k = 0; k < 11; k++) for (int l = 0; l < 2; l++) dp[i][j][k][l] = -1;
  N = to_string(b);
  int res = f(0, 10, 10, 1);
  if (a == 0) 
  {
    cout << res << '\n';
    return 0;
  }
  a--;
  for (int i = 0; i < 20; i++) for (int j = 0; j < 11; j++) for (int k = 0; k < 11; k++) for (int l = 0; l < 2; l++) dp[i][j][k][l] = -1;
  N = to_string(a);
  res -= f(0, 10, 10, 1);
  cout << res << '\n';
}

Compilation message (stderr)

numbers.cpp: In function 'long long int f(long long int, long long int, long long int, long long int)':
numbers.cpp:14:9: 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]
   14 |   if (i == N.length()) return 1;
      |       ~~^~~~~~~~~~~~~

• Subtask 1: 12.5 / 25
• Subtask 2: 60 / 75