Submission #228738

#	Time	Username	Problem	Language	Result	Execution time	Memory
228738		Haunted_Cpp	Palindrome-Free Numbers (BOI13_numbers)	C++17	100 / 100	6 ms	512 KiB

numbers

#include <iostream>
#include <vector>
#include <cstring>
#include <cassert>
#include <bitset>
 
#pragma GCC optimize ("Ofast")
#pragma GCC target("fma,sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,avx2,tune=native")
#pragma GCC optimize("unroll-loops")
 
using namespace std;

long long dp [20][11][11][2];

vector<int> lim;
const int OFF=  1;

long long solve (int p, int last1, int last2, bool started, bool tight) {
	if (p < 0) return 1;
	if (tight && ~dp[p][last1 + OFF][last2 + OFF][started]) return dp[p][last1 + OFF][last2 + OFF][started];
	long long res = 0;
	if (!started) {
		res += solve (p - 1, last1, last2, false, true);
	}
	for (int i = (started ? 0 : 1) ; i <= (tight ? 9 : lim[p]); i++) {
		int ant = last1 - OFF;
		int antant = last2 - OFF;
		int dig = i;
		if (dig != ant && dig != antant) {
			res += solve (p - 1, dig + OFF, ant + OFF, true, tight | (i < lim[p]));
		}
	}
	return (!tight ? res : dp[p][last1 + OFF][last2 + OFF][started] = res);
}

long long get_solve (long long n) {
	if (n < 0) return 0;
	lim.clear();
	while (n) {
		lim.emplace_back(n % 10);
		n /= 10;
	}
	return solve ( (int) lim.size() - 1, -1 + OFF, -1 + OFF, false, false);
}
 
int main () {
	ios::sync_with_stdio(0);
	cin.tie(0);
	memset (dp, -1, sizeof(dp));
  long long lo, hi;
  cin >> lo >> hi;
  cout << get_solve (hi) - get_solve (lo - 1) << '\n';
  return 0;
}

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