Submission #849579

#	Time	Username	Problem	Language	Result	Execution time	Memory
849579		iee	A Difficult(y) Choice (BOI21_books)	C++17	100 / 100	21 ms	1996 KiB

books

#include <bits/stdc++.h>

#include "books.h"

using namespace std;
//
// --- Sample implementation for the task books ---
//
// To compile this program with the sample grader, place:
//	 books.h books_sample.cpp sample_grader.cpp
// in a single folder and run:
//	 g++ books_sample.cpp sample_grader.cpp
// in this folder.
//

void solve(int N, int K, long long A, int S) {
	vector<int> av;
	for (int i = 1; i <= N; i++) {
		av.push_back(i);
	}
	vector<long long> mem(N + 1, -1);
	auto query = [&](int x) {
		if (mem[x] != -1) return mem[x];
		return mem[x] = skim(x);
	};
	long long sm = 0;
	for (int i = 1; i < K; i++) {
		sm += query(i);
	}
	int l = K, r = N;
	while (l < r) {
		int mid = (l + r + 1) >> 1;
		if (query(mid) + sm <= A * 2) l = mid;
		else r = mid - 1;
	}
	vector<int> p;
	for (int i = 1; i < K; i++) {
		p.push_back(i);
	}
	for (int i = l - K + 1; i <= l; i++) {
		p.push_back(i);
	}
	sort(p.begin(), p.end()), p.erase(unique(p.begin(), p.end()), p.end());
	for (int s = 0; s < (1 << p.size()); s++) {
		if (__builtin_popcount(s) == K) {
			long long sum = 0;
			vector<int> v;
			for (int i = 0; i < p.size(); i++) {
				if (s >> i & 1) {
					sum += query(p[i]);
					v.push_back(p[i]);
				}
			}
			if (sum >= A && sum <= A * 2) {
				answer(v);
			}
		}
	}
	impossible();
}

Compilation message (stderr)

books.cpp: In function 'void solve(int, int, long long int, int)':
books.cpp:48:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   48 |    for (int i = 0; i < p.size(); i++) {
      |                    ~~^~~~~~~~~~

• Subtask 1: 5 / 5
• Subtask 2: 15 / 15
• Subtask 3: 10 / 10
• Subtask 4: 15 / 15
• Subtask 5: 15 / 15
• Subtask 6: 20 / 20
• Subtask 7: 20 / 20