제출 #270461

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
270461		eohomegrownapps	Lucky Numbers (RMI19_lucky)	C++14	28 / 100	3 ms	1280 KiB

lucky

#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
ll arr[100000];
ll m = 1000000007;
ll n;

ll dp[2][2][100000];

ll f(int ind, bool isEq, bool was1){
	//cout<<ind<<' '<<isEq<<' '<<was1<<'\n';
	if (ind==n){
		return 1;
	}
	if (dp[isEq][was1][ind]!=-1){return dp[isEq][was1][ind];}
	ll tot = 0;
	for (int i = 0; i<=(isEq?arr[ind]:9); i++){
		if (was1 && i==3){continue;}
		tot+=f(ind+1,(i==arr[ind]&&isEq),(i==1));
		tot%=m;
	}
	return dp[isEq][was1][ind]=tot;
}

ll mexp(ll a, ll b){
	if (b==0){
		return 1;
	}
	ll ans = mexp(a,b/2);
	ans = (ans*ans)%m;
	if (b%2==0){
		return ans;
	} else {
		return (ans*a)%m;
	}
}

ll minv(ll x){
	return mexp(x,m-2);
}

int main(){
	ll q;
	cin>>n>>q;
	string s;
	cin>>s;
	for (ll i = 0; i<n; i++){
		arr[i]=s[i]-'0';
	}
	for (ll a = 0; a<2; a++){
		for (ll b = 0; b<2; b++){
			for (ll c = 0; c<n; c++){
				dp[a][b][c]=-1;
			}
		}
	}
	cout<<f(0,true,false)<<'\n';
}

• Subtask 1: 14 / 14
• Subtask 2: 14 / 14
• Subtask 3: 0 / 9
• Subtask 4: 0 / 27
• Subtask 5: 0 / 9
• Subtask 6: 0 / 27