Submission #308534

#	Time	Username	Problem	Language	Result	Execution time	Memory
308534		jwvg0425	Packing Biscuits (IOI20_biscuits)	C++17	100 / 100	43 ms	896 KiB

biscuits

#include "biscuits.h"
#include <stdio.h>
#include <vector>
#include <queue>
#include <algorithm>
#include <iostream>
#include <string>
#include <bitset>
#include <map>
#include <set>
#include <tuple>
#include <string.h>
#include <math.h>
#include <random>
#include <functional>
#include <assert.h>
#include <math.h>
#define all(x) (x).begin(), (x).end()
#define xx first
#define yy second

using namespace std;

template<typename T, typename Pr = less<T>>
using pq = priority_queue<T, vector<T>, Pr>;
using i64 = long long int;
using ii = pair<int, int>;
using ii64 = pair<i64, i64>;

struct Solver
{
	Solver(i64 xv, const vector<i64>& a)
		: x(xv), value(62), cnt(62), maxBit(0)
	{
		for (int i = 0; i < a.size(); i++)
			value[i] = (1ll << i) * a[i];

		for (int i = 1; i < 62; i++)
			value[i] += value[i - 1];

		i64 maxv = value[61];

		while ((1ll << maxBit) <= maxv / x)
			maxBit++;
	}

	i64 solve()
	{
		i64 res = 1;
		for (int i = 0; i < maxBit; i++)
		{
			i64 need = x * (1ll << i);
			i64 now = value[i];
			if (now < need)
				continue;

			now -= need;

			// 내려가면서, bit 위치 1인 경우 센다.
			int fst = -1;
			for (int bit = i - 1; bit >= 0; bit--)
			{
				if (now < x * (1ll << bit) ||  value[bit] < x * (1ll << bit))
					continue;

				fst = bit;
				break;
			}

			if (fst != -1)
				cnt[i] = calc(fst, now);
			else
				cnt[i] = 1;

			res += cnt[i];
		}

		return res;
	}

	i64 calc(int bit, i64 lim)
	{
		i64 res = 1; // 000..0
		for (int j = 0; j < bit; j++)
			res += cnt[j];

		lim -= x * (1ll << bit);
		i64 now = value[bit] - (x * (1ll << bit));
		lim = min(lim, now);

		bool isNxt = false;
		for (int j = bit - 1; j >= 0; j--)
		{
			if (lim < x * (1ll << j) || value[j] < x * (1ll << j))
				continue;

			res += calc(j, lim);
			isNxt = true;
			break;
		}

		if (!isNxt)
			res++;

		return res;
	}

	i64 x;
	int maxBit;
	vector<i64> value;
	vector<i64> cnt;
};

i64 count_tastiness(i64 x, vector<i64> a)
{
	Solver s(x, a);
	return s.solve();
}

Compilation message (stderr)

biscuits.cpp: In constructor 'Solver::Solver(i64, const std::vector<long long int>&)':
biscuits.cpp:111:14: warning: 'Solver::cnt' will be initialized after [-Wreorder]
  111 |  vector<i64> cnt;
      |              ^~~
biscuits.cpp:109:6: warning:   'int Solver::maxBit' [-Wreorder]
  109 |  int maxBit;
      |      ^~~~~~
biscuits.cpp:32:2: warning:   when initialized here [-Wreorder]
   32 |  Solver(i64 xv, const vector<i64>& a)
      |  ^~~~~~
biscuits.cpp:35:21: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   35 |   for (int i = 0; i < a.size(); i++)
      |                   ~~^~~~~~~~~~

• Subtask 1: 9 / 9
• Subtask 2: 12 / 12
• Subtask 3: 21 / 21
• Subtask 4: 35 / 35
• Subtask 5: 23 / 23