Submission #631261

#	Time	Username	Problem	Language	Result	Execution time	Memory
631261		uylulu	Palindrome-Free Numbers (BOI13_numbers)	C++14	72.50 / 100	1 ms	340 KiB

numbers

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

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

const int N = 18;

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

string s;

int f(int pos,int i1,int i2,int tight) {
	if(pos == s.size()) return 1;
	if(dp[pos][i1][i2][tight] != -1) return dp[pos][i1][i2][tight];
	int res = 0,lim = 9;
	if(tight) {
		lim = s[pos] - '0';
	}
	for(int i = 0;i <= lim;i++) {
		if(i == i1 || i == i2) continue;
		int ns = 0;
		if(i == lim) ns = tight;
		res += f(pos + 1,i2,i,ns);
	}
	return dp[pos][i1][i2][tight] = res;
}

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

signed main() {
	// freopen("in.txt","r",stdin);
	// freopen("out.txt","w",stdout);
	
	int a,b;
	cin>>a>>b;
	cout<<help(b) - help(a - 1);
}

Compilation message (stderr)

numbers.cpp: In function 'long long int f(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;
      |     ~~~~^~~~~~~~~~~

• Subtask 1: 12.5 / 25
• Subtask 2: 60 / 75