Submission #547547

#	Time	Username	Problem	Language	Result	Execution time	Memory
547547		LucaDantas	Packing Biscuits (IOI20_biscuits)	C++17	100 / 100	62 ms	1304 KiB

biscuits

#include "biscuits.h"
#include <cassert>
#include <algorithm>
#include <cstdio>
#include <map>

long long x;
std::vector<long long> s;

std::map<long long, long long> mp;

long long g(long long n) {
	if(n <= 0) return 0;
	if(n == 1) return 1;
	if(mp.count(n)) return mp[n];
	// retorno quantos caras menores que n são validos

	int i = 63-__builtin_clzll(n) - (__builtin_popcountll(n)==1);

	/* printf("%lld %d\n", n, i);
	fflush(stdout); */

	// opção 1: não usar o i-ésimo bit
	long long ans = g(1ll<<i);

	// opção 2: usar o i-ésimo bit, porém tenho que garantir que a soma do valor é suficiente
	// aka as: s[i] >= y*x ==(estou usando o i-ésimo bit)=> s[i]/x > (y' + 1<<i) - 1 ==> s[i]/x + 1 - (1<<i) > y'
	ans += g(std::min(n, s[i]/x + 1) - (1ll << i));

	mp[n] = ans;

	return ans;
}

long long count_tastiness(long long X, std::vector<long long> a) {
	mp.clear();
	x = X;
	s = a;
	while(s.size() < 60) s.push_back(0);
	for(int i = 1; i < s.size(); i++)
		s[i] = (1ll << i) * s[i] + s[i-1];
	return g(1ll<<60);
}

Compilation message (stderr)

biscuits.cpp: In function 'long long int count_tastiness(long long int, std::vector<long long int>)':
biscuits.cpp:40:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   40 |  for(int i = 1; i < s.size(); i++)
      |                 ~~^~~~~~~~~~

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