Submission #520011

#	Time	Username	Problem	Language	Result	Execution time	Memory
520011		PoPularPlusPlus	Palindrome-Free Numbers (BOI13_numbers)	C++17	100 / 100	2 ms	380 KiB

numbers

#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define ull unsigned long long 
#define pb(e) push_back(e)
#define sv(a) sort(a.begin(),a.end())
#define sa(a,n) sort(a,a+n)
#define mp(a,b) make_pair(a,b)
#define vf first
#define vs second
#define ar array
#define all(x) x.begin(),x.end()
const int inf = 0x3f3f3f3f;
const int mod = 1000000007; 
const double PI=3.14159265358979323846264338327950288419716939937510582097494459230;
bool remender(ll a , ll b){return a%b;}

ll dp[20][11][11][2][2];
vector<int> v;

ll rec(int i , int l1 , int l2 , int p , int s){
	if(i == (int)v.size()){
		return 1;
	}
	if(dp[i][l1][l2][p][s]!=-1)return dp[i][l1][l2][p][s];
	int last = 9;
	if(p == 1)last = v[i];
	ll res = 0;
	for(int j = 0; j <= last; j++){
		if(j != l1 && j != l2){
			if(j == last){
				if(s == 1 && j == 0)
				res += rec(i + 1 , 10 , l1 , p , 1);
				else res += rec(i + 1 , j , l1 , p , 0);
			}
			else {
				if(s == 1 && j == 0)
				res += rec(i + 1 , 10 , l1 , 0 , 1);
				else res += rec(i + 1 , j , l1 , 0 , 0);
			}
		}
	}
	return dp[i][l1][l2][p][s] = res;
}

void removedigits(ll x){
	v.clear();
	while(x){
		v.pb(x % 10);
		x /= 10;
	}
	reverse(all(v));
}

void solve(){
	ll a , b;
	cin >> a >> b;
	ll ans = 0;
	removedigits(b);
	memset(dp,-1,sizeof dp);
	ans += rec(0 , 10 , 10 , 1 , 1);
	removedigits(a-1);
	memset(dp,-1,sizeof dp);
	ans -= rec(0 , 10 , 10 , 1 , 1);
	cout << ans << '\n';
}

int main(){
ios_base::sync_with_stdio(false);
cin.tie(NULL);
	//int t;cin >> t;while(t--)
	solve();
	return 0;
}

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