Submission #1128835

#	Time	Username	Problem	Language	Result	Execution time	Memory
1128835		Agageldi	Palindrome-Free Numbers (BOI13_numbers)	C++17	100 / 100	2 ms	1864 KiB

numbers

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

#define ll long long
#define N 400005
#define ff first
#define ss second
#define pb push_back
#define sz(s) (int)s.size()

ll n, t, a[N], m, ret, l, r, dp[20][10][10][10][10];

ll solve(int pos,int last_dig,int pre_last_digit,int flag,int big_flag) {
	if(pos == 20) {
		return 1;
	}
	ll ret = dp[pos][last_dig][pre_last_digit][flag][big_flag];
	if(~ret) {
		return ret;
	}
	ret = 0;
	/*
	flag: 0 baslamady
	flag: 1 baslanymdan bir sifr gecdi
	flag: 2 baslanymdan bir sifrdan kop boldy
	bigflag: eger prefix-in hemmesi den bolsa onda 0 else 1
	*/
	for(int i = 0; i < 10; i++) {
		if(flag >= 1 && last_dig == i) continue;
		if(flag == 2 && pre_last_digit == i) continue;
		if(big_flag == 0 && i > a[pos]) continue;
		int new_big_flag = (big_flag | (i < a[pos]));
		int new_flag = min(2,flag + (flag | (i != 0)));
		ret += solve(pos + 1,i,last_dig,new_flag,new_big_flag);
	}
	dp[pos][last_dig][pre_last_digit][flag][big_flag] = ret;
	return ret;
}
ll f(ll x){
	if(x < 0)
		return 0;
	memset(dp,-1,sizeof dp);
	for(int i = 19; i >= 0; i--) {
		a[i] = x % 10;
		x /= 10;
	}
	return solve(0,0,0,0,0);
}

int main () {
	ios::sync_with_stdio(0);cin.tie(0);
	cin >> l >> r;
	cout << f(r) - f(l-1) <<'\n';
}

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