Submission #631271

#	Time	Username	Problem	Language	Result	Execution time	Memory
631271		uylulu	Palindrome-Free Numbers (BOI13_numbers)	C++14	100 / 100	1 ms	388 KiB

numbers

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

#define int long long
#define ld long double
#define endl "\n"

const int N = 19;

int dp[N + 1][12][12][2][2];

string s;

int f(int pos,int i1,int i2,int tight,int front) {
	if(pos == s.size()) return 1;
	if(dp[pos][i1][i2][tight][front] != -1) return dp[pos][i1][i2][tight][front];
	int res = 0,lim = 9;
	if(tight) {
		lim = s[pos] - '0';
	}
	for(int i = 0;i <= lim;i++) {
		if(i == i1 || i == i2) {
			if(i == 0) {
				if(!front) continue;
			} else continue;
		}
		int ns = 0;
		int asd = front;
		if(i2 != 0 && i2 != 11) asd = false;
		if(i == lim) ns = tight;
		res += f(pos + 1,i2,i,ns,asd);
	}
	// cout<<pos<<" "<<i1<<" "<<i2<<" "<<front<<" "<<res<<" "<<lim<<endl;
	return dp[pos][i1][i2][tight][front] = res;
}

int help(int x) {
	s = to_string(x);
	memset(dp,-1,sizeof(dp));
	return f(0,11,11,1,true);
}

bool check(string temp) {
	for(int i = 1;i < temp.size();i++) {
		if(temp[i] == temp[i - 1]) return false;
		if(i >= 2 && temp[i] == temp[i - 2]) return false;
	}
	return true;
}

int cnt(int x) {
	int res = 0;
	for(int i = 0;i <= x;i++) {
		res += check(to_string(i));
	}
	return res;
}

signed main() {
	// freopen("in.txt","r",stdin);
	// freopen("out.txt","w",stdout);

	int a,b;
	cin>>a>>b;
	if(a == 0) {
		cout<<help(b)<<endl;
	} else {
		cout<<help(b) - help(a - 1)<<endl;
	}
}

Compilation message (stderr)

numbers.cpp: In function 'long long int f(long long int, long long int, long long int, long long int, long long int)':
numbers.cpp:15:9: 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]
   15 |  if(pos == s.size()) return 1;
      |     ~~~~^~~~~~~~~~~
numbers.cpp: In function 'bool check(std::string)':
numbers.cpp:44:18: 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]
   44 |  for(int i = 1;i < temp.size();i++) {
      |                ~~^~~~~~~~~~~~~

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