Submission #223771

#	Time	Username	Problem	Language	Result	Execution time	Memory
223771		Bruteforceman	Palindrome-Free Numbers (BOI13_numbers)	C++11	100 / 100	5 ms	384 KiB

numbers

#include <bits/stdc++.h>
using namespace std;
vector <int> v;
long long mem[20][2][2][11][11];

long long dp(int cur, int big, int start, int p1, int p2) {
  if(cur == v.size()) return 1;
  int range = big ? 9 : v[cur];
  long long &ans = mem[cur][big][start][p1][p2];
  if(ans != -1) return ans;
  ans = 0;
  for(int i = 0; i <= range; i++) {
    if(p1 == i || p2 == i) continue;
    ans += dp(cur + 1, big || (i < v[cur]), start || i, p2, (start || i) ? i : 10);
  }
  return ans;
}

long long count(long long x) {
  memset(mem, -1, sizeof mem);
  v.clear();
  while(x) {
    v.push_back(x % 10);
    x /= 10;
  }
  reverse(v.begin(), v.end());
  return dp(0, 0, 0, 10, 10);
}
int main() {
  long long l, r;
  cin >> l >> r;
  cout << count(r) - count(l - 1) << endl;
  return 0;
}

Compilation message (stderr)

numbers.cpp: In function 'long long int dp(int, int, int, int, int)':
numbers.cpp:7:10: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   if(cur == v.size()) return 1;
      ~~~~^~~~~~~~~~~

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