Submission #723788

#	Time	Username	Problem	Language	Result	Execution time	Memory
723788		Juan	Palindrome-Free Numbers (BOI13_numbers)	C++17	73.75 / 100	1 ms	304 KiB

numbers

#include<bits/stdc++.h>
using namespace std;
#define int long long


int solve(int n){
	if(n<10) return n+1;
	if(n<100) return n+1 - n/11;

	int rt = 81;
	string s = to_string(n);
	rt *= pow(8, max(0LL, (int)s.size()-3));
	rt += (s[0]-'0'-1) * 9 * pow(8, s.size()-2);

	for(int i = 1; i < s.size(); i++){
		int niii=10;
		int ni = s[i]-'0';
		int nii = s[i-1]-'0';
		if(i>=2) niii = s[i-2]-'0';
		rt += max(ni -(nii<ni) -(niii<ni), 0LL) * pow(8, max(0LL, (int)s.size()-i-1));

		if((i>=1 && s[i]==s[i-1]) || (i>=2 && s[i]==s[i-2])) break;
		if(i==s.size()-1) rt++;
	}

	return rt;
}

int32_t main(){
	int a, b; cin >> a >> b;
	cout << solve(b) - solve(a-1) << '\n';
}

Compilation message (stderr)

numbers.cpp: In function 'long long int solve(long long int)':
numbers.cpp:15:19: 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]
   15 |  for(int i = 1; i < s.size(); i++){
      |                 ~~^~~~~~~~~~
numbers.cpp:23:7: 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]
   23 |   if(i==s.size()-1) rt++;
      |      ~^~~~~~~~~~~~

• Subtask 1: 13.75 / 25
• Subtask 2: 60 / 75