oj.uz

Submission #45022

# Submission time Handle Problem Language Result Execution time Memory
45022 2018-04-10T16:45:28 Z zadrga Hidden Sequence (info1cup18_hidden) C++14
100 / 100
 66 ms 588 KB 
#include <bits/stdc++.h>

using namespace std;

#define pb push_back
#define mp make_pair
#define fi first
#define se second
#define INF (1LL << 55)
#define MOD (1000 * 1000 * 1000 + 7)
#define maxn 3111

typedef long long ll;
typedef long double ld;
typedef pair<int, int> pii;

bool isSubsequence(vector<int> v);

int pre[maxn];

bool ask(int cur, int lf, int rg){
	vector<int> q;
	while(lf--)
		q.pb(cur);

	cur ^= 1;

	while(rg--)
		q.pb(cur);

	return isSubsequence(q);
}


vector<int> findSequence(int N){
	int lim = N / 2 + 1, K = -1, less = -1;
	for(int i = 0; i <= N / 2; i++){
		if(ask(0, i + 1, 0) == 0){
			K = i;
			less = 0;
			break;
		}
		if(ask(1, i + 1, 0) == 0){
			K = i;
			less = 1;
			break;
		}
	}

	pre[0] = 0;
	pre[K + 1] = N - K;
	for(int i = 1; i <= K; i++){
		pre[i] = pre[i - 1];
		bool q = 1;

		while(pre[i] + K + 1 - i <= lim){
			q = ask(less ^ 1, pre[i], K + 1 - i);
			if(q == 0){
				pre[i]--;
				break;
			}
			pre[i]++;
		}

		if(q == 0)
			continue;

		int rev = 0;
		while(i + rev <= lim){
			q = ask(less, i, rev);
			if(q == 0){
				rev--;
				break;
			}
			rev++;
		}

		if(q == 0)
			pre[i] = N - K - rev;
		
		else{						
			rev--;					//in this case I'm right at half of it, and couldn't afford asking one more query
			pre[i] = N - K - rev;		//the answer to that query, however, should've been negative anyways, so there'pre no problem actually
		}
	}

	for(int i = K + 1; i >= 1; i--)
		pre[i] -= pre[i - 1];

	vector<int> ans;
	for(int i = 1; i <= K + 1; i++){
		while(pre[i]--)
			ans.pb(less ^ 1);

		if(i != K + 1)
			ans.pb(less);
	}
	return ans;
}

Compilation message

grader.cpp: In function 'int main()':
grader.cpp:28:43: warning: format '%d' expects argument of type 'int', but argument 3 has type 'std::vector<int>::size_type {aka long unsigned int}' [-Wformat=]
     fprintf (fifo_out, "%d\n", ans.size ());
                                ~~~~~~~~~~~^
grader.cpp:29:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for (int i=0; i<ans.size () && i < N; i++)
                   ~^~~~~~~~~~~~

Subtask #1
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 248 KB Output is correct: Maximum length of a query = 5
2 Correct 2 ms 436 KB Output is correct: Maximum length of a query = 6
3 Correct 2 ms 436 KB Output is correct: Maximum length of a query = 5
4 Correct 2 ms 452 KB Output is correct: Maximum length of a query = 5
5 Correct 2 ms 452 KB Output is correct: Maximum length of a query = 4

Subtask #2
80.0 / 80.0

# Verdict Execution time Memory Grader output
1 Correct 39 ms 452 KB Output is correct: Maximum length of a query = 83
2 Correct 39 ms 532 KB Output is correct: Maximum length of a query = 90
3 Correct 20 ms 532 KB Output is correct: Maximum length of a query = 96
4 Correct 25 ms 536 KB Output is correct: Maximum length of a query = 77
5 Correct 13 ms 544 KB Output is correct: Maximum length of a query = 95
6 Correct 6 ms 560 KB Output is correct: Maximum length of a query = 87
7 Correct 30 ms 560 KB Output is correct: Maximum length of a query = 97
8 Correct 21 ms 568 KB Output is correct: Maximum length of a query = 83
9 Correct 57 ms 568 KB Output is correct: Maximum length of a query = 101
10 Correct 66 ms 568 KB Output is correct: Maximum length of a query = 100
11 Correct 10 ms 580 KB Output is correct: Maximum length of a query = 96
12 Correct 8 ms 580 KB Output is correct: Maximum length of a query = 100
13 Correct 34 ms 588 KB Output is correct: Maximum length of a query = 101