Submission #821808

#	Time	Username	Problem	Language	Result	Execution time	Memory
821808		Thanhs	Palindrome-Free Numbers (BOI13_numbers)	C++14	100 / 100	1 ms	340 KiB

numbers

#pragma GCC optimize("Ofast")
#pragma GCC optimize("unroll-loops")
#include <bits/stdc++.h>
using namespace std;
 
#define int long long
typedef long double ld;
typedef vector<int> vi;
typedef vector<vi> vvi;
typedef stack<int> si;
typedef queue<int> qi;
typedef deque<int> di;
typedef pair<int, int> pii;
typedef vector<pii> vpii;

#define endl '\n'
#define pb push_back
#define FOR(i,g,b) for(int i = g; i <= b; i++)
#define BACK(i,g,b) for(int i = g; i >= b; i--)
#define fastIO ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0);
#define fi first
#define se second
#define gcd __gcd
#define setmin(x,y) x=min((x),(y))
#define setmax(x,y) x=max((x),(y))

const int MAXN=(1e6)+5;
const int inf=1e18;
const int MOD=1e9+7;

int dp[20][11][11][2][2],a,b,cnt=0;
vi dig;

int bt(int idx,int p1,int p2,bool k1,bool k2)
{
	cnt++;
	if(idx==(int)(dig.size())) return 1;
	if(~dp[idx][p1][p2][k1][k2]) return dp[idx][p1][p2][k1][k2];
	int res=0;
	FOR(i,0,(k1?9:dig[idx])) if(i!=p1&&i!=p2) res+=bt(idx+1,p2,(!i&&!k2?10:i),k1|(i<dig[idx]),k2|(i>0));
	return dp[idx][p1][p2][k1][k2]=res;
}

int solve(int x)
{
	memset(dp,-1,sizeof dp);
	dig.clear();
	while(x) {dig.pb(x%10); x/=10;}
	reverse(dig.begin(),dig.end());
	return bt(0,10,10,0,0);
}

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

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