Submission #950111

#	Time	Username	Problem	Language	Result	Execution time	Memory
950111		pcc	A Difficult(y) Choice (BOI21_books)	C++17	60 / 100	2 ms	688 KiB

books

#include <bits/stdc++.h>

#include "books.h"

using namespace std;

#define ll long long
#define pll pair<ll,ll>
#define fs first
#define sc second
//
// --- 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(int k){
	if(mp.find(k) != mp.end())return mp[k];
	else return mp[k] = skim(k);
}

void solve(int N, int K, long long A, int S) {
    // TODO implement this function
	vector<pll> v;
	ll sum = 0;
	ll big = 0;
	ll l = 1,r = N+1;
	while(l != r){
		ll mid = (l+r)>>1;
		if(ask(mid)>=A)r = mid;
		else l = mid+1;
	}
	big = r;
	if(big<=N&&big>=K){
		ll sum = ask(big);
		vector<int> v;
		v.push_back(big);
		for(int i = 1;i<K;i++){
			v.push_back(i);
			sum += ask(i);
		}
		if(sum>=A&&sum<=A*2){
			answer(v);
			return;
		}
	}
	if(big<K){
		impossible();
		return;
	}
	for(int i = 1;i<=K;i++){
		v.push_back(pll(i,ask(i)));
		sum += v.back().sc;
	}
	for(int i = K-1;i>=0;i--){
		if(sum>=A&&sum<=A*2)break;
		ll l = i+1,r = (i+1==v.size()?big-1:v[i+1].fs-1);
		while(l != r){
			ll mid = (l+r)>>1;
			if(ask(mid)+sum-v[i].sc>=A)r = mid;
			else l = mid+1;
		}
		sum -= v[i].sc;
		v[i] = pll(l,ask(l));
		sum += v[i].sc;
	}
	if(sum<A||sum>A*2){
		impossible();
		return;
	}
	vector<int> ans;
	for(auto &i:v)ans.push_back(i.fs);
	answer(ans);
}

Compilation message (stderr)

books.cpp: In function 'void solve(int, int, long long int, int)':
books.cpp:71:22: 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]
   71 |   ll l = i+1,r = (i+1==v.size()?big-1:v[i+1].fs-1);
      |                   ~~~^~~~~~~~~~

• Subtask 1: 5 / 5
• Subtask 2: 15 / 15
• Subtask 3: 10 / 10
• Subtask 4: 15 / 15
• Subtask 5: 15 / 15
• Subtask 6: 0 / 20
• Subtask 7: 0 / 20