Submission #564194

#	Time	Username	Problem	Language	Result	Execution time	Memory
564194		SSRS	Palindrome-Free Numbers (BOI13_numbers)	C++14	100 / 100	1 ms	348 KiB

numbers

#include <bits/stdc++.h>
using namespace std;
long long solve(long long N){
  string S = to_string(N);
  int L = S.size();
  vector<vector<vector<vector<long long>>>> dp(L + 1, vector<vector<vector<long long>>>(2, vector<vector<long long>>(10, vector<long long>(10, 0))));
  dp[L][1][0][0] = 1;
  long long ans = 0;
  if (N > 0){
    ans++;
  }
  for (int i = L; i >= 0; i--){
    for (int j = 0; j < 2; j++){
      for (int k = 0; k < 10; k++){
        for (int l = 0; l < 10; l++){
          if (!(i == 0 && j == 1) && l > 0){
            ans += dp[i][j][k][l];
          }
          if (i > 0){
            for (int m = 0; m < 10; m++){
              bool ok = true;
              if (i < L && m == l){
                ok = false;
              }
              if (i < L - 1 && m == k){
                ok = false;
              }
              if (ok){
                int j2 = j;
                if (m > S[i - 1] - '0'){
                  j2 = 1;
                } else if (m < S[i - 1] - '0'){
                  j2 = 0;
                }
                dp[i - 1][j2][l][m] += dp[i][j][k][l];
              }
            }
          }
        }
      }
    }
  }
  return ans;
}
int main(){
  long long a, b;
  cin >> a >> b;
  cout << solve(b + 1) - solve(a) << endl;
}

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