Submission #523519

#	Time	Username	Problem	Language	Result	Execution time	Memory
523519		fatemetmhr	A Difficult(y) Choice (BOI21_books)	C++17	0 / 100	2 ms	2632 KiB

books

// Be name khoda //
#include <bits/stdc++.h>
#include "books.h"

using namespace std;

typedef long long ll;

const int maxn5 = 3e5 + 10;
const int lg    = 20;

#define pb    push_back
#define se    second
#define fi    first

//
// --- 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.
//

int n, k, s;
ll A, have;
ll a[maxn5];

inline bool check(int pre){
	ll have = 0;
	if(a[pre + 1] == -1)
		a[pre + 1] = skim(pre + 1);
	for(int i = 1; i <= pre + 1; i++)
		have += a[i];
	for(int i = n - (k - 1 - pre) + 1; i <= n; i++)
		have += a[i];
	return have >= A;
}

inline bool ok(int id){
	return have + skim(id) <= A;
}


void solve(int N, int K, long long AA, int S) {
	n = N;
	k = K;
	s = S;
	A = AA;
	memset(a, -1, sizeof a);
	
	for(int i = 1; i <= k; i++)
		a[i] = skim(i);
	for(int i = n - k + 1; i <= n; i++)
		a[i] = skim(i);
	
	int lo = 0, hi = k;
	while(hi - lo > 1){
		int mid = (lo + hi) >> 1;
		if(check(mid)) lo = mid;
		else hi = mid;
	}
		
	if(lo == 0){
		have = 0;
		for(int i = n - k + 1; i <= n; i++)
			have += a[i];
		if(have < A)
			impossible();
	}
	
	if(lo == k){
		have = 0;
		for(int i = 1; i <= k; i++)
			have += a[i];
		if(have > 2 * A)
			impossible();
	}
	
	have = 0;
	for(int i = 1; i <= lo; i++)
		have += a[i];
	for(int i = n - (k - 1 - lo) + 1; i <= n; i++)
		have += a[i];
	
	int l = lo + 1, r = n - (k - 1 - lo) + 1;
	while(r - l > 1){
		int mid = (l + r) >> 1;
		if(ok(mid))
			l = mid;
		else
			r = mid;
	}
	
	vector <int> ret;
	ret.clear();
	for(int i = 1; i <= lo; i++)
		ret.pb(i);
	ret.pb(l);
	for(int i = n - (k - 1 - lo) + 1; i <= n; i++)
		ret.pb(i);
	
	answer(ret);
	
    if (skim(2) == 42) {
        impossible();
    } else {
        answer({1, 3});
    }
}

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