Submission #950903

#	Time	Username	Problem	Language	Result	Execution time	Memory
950903		pcc	A Difficult(y) Choice (BOI21_books)	C++17	100 / 100	14 ms	608 KiB

books

#include <bits/stdc++.h>

#include "books.h"
#define ll long long
#define pll pair<ll,ll>
#define fs first
#define sc second

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.
//

if (skim(2) == 42) {
	impossible();
} else {
	answer({1, 3});
}
*/

map<ll,ll> mp;
ll ask(ll p){
	if(mp.find(p) != mp.end())return mp[p];
	else return mp[p] = skim(p);
}

void solve(int N, int K, long long A, int S) {
	mp.clear();
	vector<pll> v;
	ll sum = 0;
	for(int i = 1;i<=K;i++){
		v.push_back(pll(i,ask(i)));
	}
	ll l = 1,r = N+1;
	while(l+1<r){
		ll mid = (l+r)>>1;
		if(ask(mid)>=A)r = mid;
		else l = mid;
	}
	if(r != N+1){
		ll sum = ask(r);
		int cnt = 1;
		vector<int> ans = {r};
		for(int i = 1;i<=K;i++){
			if(ans.size()>=K)break;
			if(i == ans[0])continue;
			ans.push_back(i);
			sum += ask(i);
		}
		if(sum>=A&&sum<=A*2){
			answer(ans);
			return;
		}
	}
	for(int i = 1;i<=K;i++){
		if(r-i>0)v.push_back(pll(r-i,ask(r-i)));
	}
	sort(v.begin(),v.end());
	v.erase(unique(v.begin(),v.end()),v.end());
	for(int i = 0;i<(1<<v.size());i++){
		if(__builtin_popcount(i) != K)continue;
		ll sum = 0;
		for(int j = 0;j<v.size();j++){
			if(i&(1<<j))sum += v[j].sc;
		}
		if(sum>=A&&sum<=A*2){
			vector<int> ans;
			for(int j = 0;j<v.size();j++){
				if(i&(1<<j))ans.push_back(v[j].fs);
			}
			answer(ans);
			return;
		}
	}
	impossible();
	return;
}

Compilation message (stderr)

books.cpp: In function 'void solve(int, int, long long int, int)':
books.cpp:50:22: warning: narrowing conversion of 'r' from 'long long int' to 'int' [-Wnarrowing]
   50 |   vector<int> ans = {r};
      |                      ^
books.cpp:50:22: warning: narrowing conversion of 'r' from 'long long int' to 'int' [-Wnarrowing]
books.cpp:52:17: warning: comparison of integer expressions of different signedness: 'std::vector<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   52 |    if(ans.size()>=K)break;
      |       ~~~~~~~~~~^~~
books.cpp:49:7: warning: unused variable 'cnt' [-Wunused-variable]
   49 |   int cnt = 1;
      |       ^~~
books.cpp:70:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<long long int, long long int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   70 |   for(int j = 0;j<v.size();j++){
      |                 ~^~~~~~~~~
books.cpp:75:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<long long int, long long int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   75 |    for(int j = 0;j<v.size();j++){
      |                  ~^~~~~~~~~
books.cpp:37:5: warning: unused variable 'sum' [-Wunused-variable]
   37 |  ll sum = 0;
      |     ^~~

• 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