Submission #826298

#	Time	Username	Problem	Language	Result	Execution time	Memory
826298		Tsovak	Fibonacci representations (CEOI18_fib)	C++17	50 / 100	4014 ms	3152 KiB

fib

// -------------------- Includes -------------------- //
#define _CRT_SECURE_NO_WARNINGS
#define _USE_MATH_DEFINES
#include <iostream>
#include <iomanip>
#include <cstdio>
#include <stdio.h>
#include <cstdlib>
#include <stdlib.h>
#include <array>
#include <string>
#include <cstring>
#include <algorithm>
#include <cmath>
#include <math.h>
#include <set>
#include <map>
#include <unordered_set>
#include <unordered_map>
#include <vector>
#include <stack>
#include <queue>
#include <deque>
#include <bitset>
#include <list>
#include <iterator>
#include <numeric>
#include <complex>
#include <tuple>
#include <utility>
#include <cassert>
#include <assert.h>
#include <climits>
#include <limits.h>
#include <ctime>
#include <time.h>
#include <random>
#include <chrono>
#include <fstream>
using namespace std;

// -------------------- Typedefs -------------------- //

typedef long long ll;
typedef unsigned long long ull;
typedef double db;
typedef long double ld;

// -------------------- Defines -------------------- //

#define pr pair
#define mpr make_pair
#define ff first
#define ss second

#define mset multiset
#define mmap multimap
#define uset unordered_set
#define umap unordered_map
#define umset unordered_multiset
#define ummap unordered_multimap
#define pqueue priority_queue

#define sz(x) (int((x).size()))
#define len(x) (int((x).length()))
#define all(x) (x).begin(), (x).end()
#define rall(x) (x).rbegin(), (x).rend()
#define clr(x) (x).clear()

#define pf push_front
#define pb push_back
#define popf pop_front
#define popb pop_back
#define ft front
#define bk back

#define lb lower_bound
#define ub upper_bound
#define bs binary_search

// -------------------- Constants -------------------- //

const int MAX = int(1e9 + 5);
const ll MAXL = ll(1e18 + 5);
const ll MOD = ll(1e9 + 7);
const ll MOD2 = ll(998244353);

// -------------------- Functions -------------------- //

void fastio()
{
	ios_base::sync_with_stdio(false);
	cin.tie(0);
	cout.tie(0);
	return;
}

void precision(int x)
{
	cout.setf(ios::fixed | ios::showpoint);
	cout.precision(x);
	return;
}

ll gcd(ll a, ll b)
{
	while (b) {
		a %= b;
		swap(a, b);
	}
	return a;
}

ll lcm(ll a, ll b)
{
	return a / gcd(a, b) * b;
}

bool is_prime(ll a)
{
	if (a == 1) {
		return false;
	}
	for (ll i = 2; i * i <= a; i++) {
		if (a % i == 0) {
			return false;
		}
	}
	return true;
}

bool is_square(ll a)
{
	ll b = ll(sqrt(a));
	return (b * b == a);
}

bool is_cube(ll a)
{
	ll b = ll(cbrt(a));
	return (b * b * b == a);
}

int digit_sum(ll a)
{
	int sum = 0;
	while (a) {
		sum += int(a % 10);
		a /= 10;
	}
	return sum;
}

ll binpow(ll a, int b)
{
	ll ans = 1;
	while (b) {
		if ((b & 1) == 1) {
			ans *= a;
		}
		b >>= 1;
		a *= a;
	}
	return ans;
}

ll binpow_by_mod(ll a, ll b, ll mod)
{
	ll ans = 1;
	while (b) {
		if ((b & 1) == 1) {
			ans *= a;
			ans %= mod;
		}
		b >>= 1;
		a *= a;
		a %= mod;
	}
	return ans;
}

ll factorial(int a)
{
	ll ans = 1;
	for (int i = 2; i <= a; i++) {
		ans *= ll(i);
	}
	return ans;
}

ll factorial_by_mod(int a, ll mod)
{
	ll ans = 1;
	for (int i = 2; i <= a; i++) {
		ans *= ll(i);
		ans %= mod;
	}
	return ans;
}

// -------------------- Solution -------------------- //

const int N = 100005;
int a[N];
int n;

set<int> st;
vector<int> v;

void add(int x)
{
	if (st.empty()) {
		st.insert(x);
		return;
	}

	int i, j;

	auto it = st.lb(x);

	if (it == st.end()) {
		it--;
		if (*it == x - 1) {
			st.erase(it);
			st.insert(x + 1);
		}
		else st.insert(x);

		return;
	}

	if (*it == x + 1) {
		st.erase(it);
		add(x + 2);
		return;
	}

	if (it != st.begin()) {
		it--;
		if (*it == x - 1) {
			st.erase(it);
			add(x + 1);
			return;
		}
		it++;
	}

	if (*it >= x + 2) {
		st.insert(x);
		return;
	}

	st.erase(it);

	if (x == 1) add(2);
	else if (x == 2) {
		add(1);
		add(3);
	}
	else {
		add(x - 2);
		add(x + 1);
	}

	return;
}

ll dp[N][2];

void solve()
{
	int i, j;

	cin >> n;
	for (i = 1; i <= n; i++) {
		cin >> a[i];
	}

	for (i = 1; i <= n; i++) {
		add(a[i]);
		
		clr(v);
		for (auto j : st) v.pb(j);

		dp[0][0] = 1;
		dp[0][1] = ((v[0] + 1) / 2 - 1) % MOD;

		for (j = 1; j < sz(v); j++) {
			dp[j][0] = (dp[j - 1][0] + dp[j - 1][1]) % MOD;
			dp[j][1] = (((v[j] - v[j - 1] - 1) / 2) * dp[j - 1][0]) % MOD;
			dp[j][1] += (((v[j] - v[j - 1]) / 2) * dp[j - 1][1]) % MOD;
			dp[j][1] %= MOD;
		}

		cout << (dp[sz(v) - 1][0] + dp[sz(v) - 1][1]) % MOD << "\n";
	}

	return;
}

void precalc()
{
	return;
}

int main()
{
	fastio();

	precalc();

	int tests = 1, tc;
	//cin >> tests;
	for (tc = 1; tc <= tests; tc++) {
		solve();
	}

	//cout << db(clock()) / CLOCKS_PER_SEC << endl;

	return 0;
}

/*
	# # # #   # # # #   # # # #   #       #    #       #     #
	   #      #         #     #    #     #    # #      #   #
	   #      # # # #   #     #     #   #    #   #     # #
	   #            #   #     #      # #    # # # #    #   #
	   #      # # # #   # # # #       #    #       #   #     #
*/

Compilation message (stderr)

fib.cpp: In function 'void add(int)':
fib.cpp:217:6: warning: unused variable 'i' [-Wunused-variable]
  217 |  int i, j;
      |      ^
fib.cpp:217:9: warning: unused variable 'j' [-Wunused-variable]
  217 |  int i, j;
      |         ^

• Subtask 1: 5 / 5
• Subtask 2: 20 / 20
• Subtask 3: 15 / 15
• Subtask 4: 10 / 10
• Subtask 5: 0 / 15
• Subtask 6: 0 / 35