Submission #392326

#	Time	Username	Problem	Language	Result	Execution time	Memory
392326		johutha	Packing Biscuits (IOI20_biscuits)	C++17	100 / 100	19 ms	1332 KiB

biscuits

#include "biscuits.h"
#include <iostream>

#define int long long
#define lint __int128

using namespace std;

int count_tastiness(int x, vector<int> a)
{
	const int m = 64;

	vector<int> pref_dp(m);
	vector<int> dp(m);
	vector<lint> avs(m);

	dp[0] = 1;
	a.resize(m);

	avs[0] = 0;
	lint pw = 1;
	for (int i = 0; i < m - 1; i++, pw *= 2)
	{
		avs[i + 1] = avs[i] + pw * (lint)a[i];
	}
	// cerr << 0 << " " << dp[0] << "\n";

	pw = 1;
	for (int i = 1; i < m; i++, pw *= 2)
	{
		pref_dp[i] = dp[i - 1] + pref_dp[i - 1];
		if (avs[i] < pw*x) continue;

		lint b = avs[i] - pw*x;
		lint np = pw / 2;

		// cerr << "Starting " << i << " with " << avs[i] << ", after subtracting " << b << "\n";

		for (int j = i - 1; j >= 0; j--, np /= 2)
		{
			b = min(b, avs[j]);
			// cerr << " -> " << j << " " << b << " " << np << "\n";
			if (b >= np * x)
			{
				dp[i] += pref_dp[j];
				b -= np*x;
			}
		}
		if (b >= 0) dp[i]++;
		// cerr << i << " " << dp[i] << "\n";
	}
	return dp[m - 1] + pref_dp[m - 1];
}

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