oj.uz

Submission #751615

# Submission time Handle Problem Language Result Execution time Memory
751615 2023-06-01T01:36:45 Z rxlfd314 Sequence (APIO23_sequence) C++17
28 / 100
 453 ms 31688 KB 
#include "sequence.h"
#include <bits/stdc++.h>
using namespace std;
using ari2 = array<int, 2>;

int sequence(int N, vector<int> A) {
	if (N <= 2000) {
		int ans = 1;
		for (int i = 0; i < N; i++) {
			vector<int> cnt(N+1, 0);
			multiset<ari2> stuff;
			cnt[A[i]]++;
			stuff.insert({A[i], -i});
			ari2 med = {A[i], -i};
			for (int j = i+1; j < N; j++) {
				stuff.insert({A[j], -j});
				cnt[A[j]]++;
				if (ari2{A[j], -j} < med && (j - i & 1)) {
					med = *prev(stuff.find(med));
				} else if (ari2{A[j], -j} > med && !(j - i & 1)) {
					med = *next(stuff.find(med));
				}
				ans = max(ans, cnt[med[0]]);
				if (j - i & 1) {
					auto [a, b] = *next(stuff.find(med));
					ans = max(ans, cnt[a]);
				}
			}
		}
		return ans;
	}
	
	int middle = max_element(A.begin(), A.end()) - A.begin();
	bool mountain = true;	
	for (int i = middle - 1; i >= 0 && mountain; i--) {
		mountain &= A[i] <= A[i+1];
	}
	for (int i = middle + 1; i < N && mountain; i++) {
		mountain &= A[i] <= A[i-1];
	}
	if (mountain) {
		vector<int> inds[N];
		for (int i = 0; i < N; i++) {
			inds[A[i]-1].push_back(i);
		}
		
		int ans = 0;
		for (int ii = 0; ii < N; ii++) {
			if (inds[ii].size() < 2) {
				ans = max(ans, (int)inds[ii].size());
				continue;
			}
			int l1 = inds[ii][0], r1 = -1, l2 = -1, r2 = inds[ii].back();
			for (int i = 1; i < inds[ii].size(); i++) {
				if (inds[ii][i-1]+1 < inds[ii][i]) {
					r1 = inds[ii][i-1];
					l2 = inds[ii][i];
					break;
				}
			}
			if (r1 < 0) {
				ans = max(ans, r2 - l1 + 1);
			} else {
				int gap = l2 - r1 - 1;
				if (gap > r1 - l1 + 1 + r2 - l2 + 1) {
					if (l1 + N - r2 - 1 >= gap - (r1 - l1 + 1 + r2 - l2 + 1)) {
						ans = max(ans, r1 - l1 + 1 + r2 - l2 + 1);
					}
				} else {
					ans = max(ans, r1 - l1 + 1 + r2 - l2 + 1);
				}
			}
		}
		
		return ans;
	}
}

Compilation message

sequence.cpp: In function 'int sequence(int, std::vector<int>)':
sequence.cpp:18:36: warning: suggest parentheses around '-' in operand of '&' [-Wparentheses]
   18 |     if (ari2{A[j], -j} < med && (j - i & 1)) {
      |                                  ~~^~~
sequence.cpp:20:44: warning: suggest parentheses around '-' in operand of '&' [-Wparentheses]
   20 |     } else if (ari2{A[j], -j} > med && !(j - i & 1)) {
      |                                          ~~^~~
sequence.cpp:24:11: warning: suggest parentheses around '-' in operand of '&' [-Wparentheses]
   24 |     if (j - i & 1) {
      |         ~~^~~
sequence.cpp:54:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   54 |    for (int i = 1; i < inds[ii].size(); i++) {
      |                    ~~^~~~~~~~~~~~~~~~~
sequence.cpp:77:1: warning: control reaches end of non-void function [-Wreturn-type]
   77 | }
      | ^

Subtask #1
11.0 / 11.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 212 KB Output is correct
2 Correct 0 ms 212 KB Output is correct
3 Correct 0 ms 212 KB Output is correct
4 Correct 1 ms 212 KB Output is correct
5 Correct 2 ms 212 KB Output is correct
6 Correct 1 ms 212 KB Output is correct
7 Correct 1 ms 212 KB Output is correct
8 Correct 1 ms 212 KB Output is correct
9 Correct 1 ms 212 KB Output is correct
10 Correct 1 ms 212 KB Output is correct
11 Correct 1 ms 212 KB Output is correct
12 Correct 1 ms 212 KB Output is correct

Subtask #2
17.0 / 17.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 212 KB Output is correct
2 Correct 0 ms 212 KB Output is correct
3 Correct 0 ms 212 KB Output is correct
4 Correct 1 ms 212 KB Output is correct
5 Correct 2 ms 212 KB Output is correct
6 Correct 1 ms 212 KB Output is correct
7 Correct 1 ms 212 KB Output is correct
8 Correct 1 ms 212 KB Output is correct
9 Correct 1 ms 212 KB Output is correct
10 Correct 1 ms 212 KB Output is correct
11 Correct 1 ms 212 KB Output is correct
12 Correct 1 ms 212 KB Output is correct
13 Correct 430 ms 392 KB Output is correct
14 Correct 417 ms 388 KB Output is correct
15 Correct 425 ms 392 KB Output is correct
16 Correct 417 ms 460 KB Output is correct
17 Correct 421 ms 392 KB Output is correct
18 Correct 341 ms 340 KB Output is correct
19 Correct 442 ms 392 KB Output is correct
20 Correct 453 ms 388 KB Output is correct
21 Correct 431 ms 392 KB Output is correct
22 Correct 429 ms 340 KB Output is correct

Subtask #3
0.0 / 7.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 212 KB Output is correct
2 Correct 82 ms 25816 KB Output is correct
3 Correct 83 ms 25804 KB Output is correct
4 Correct 45 ms 17920 KB Output is correct
5 Correct 78 ms 24872 KB Output is correct
6 Correct 81 ms 24904 KB Output is correct
7 Incorrect 47 ms 18388 KB Output isn't correct
8 Halted 0 ms 0 KB -

Subtask #4
0.0 / 12.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 212 KB Output is correct
2 Incorrect 46 ms 18984 KB Output isn't correct
3 Halted 0 ms 0 KB -

Subtask #5
0.0 / 13.0

# Verdict Execution time Memory Grader output
1 Incorrect 131 ms 31688 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #6
0.0 / 22.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 212 KB Output is correct
2 Correct 0 ms 212 KB Output is correct
3 Correct 0 ms 212 KB Output is correct
4 Correct 1 ms 212 KB Output is correct
5 Correct 2 ms 212 KB Output is correct
6 Correct 1 ms 212 KB Output is correct
7 Correct 1 ms 212 KB Output is correct
8 Correct 1 ms 212 KB Output is correct
9 Correct 1 ms 212 KB Output is correct
10 Correct 1 ms 212 KB Output is correct
11 Correct 1 ms 212 KB Output is correct
12 Correct 1 ms 212 KB Output is correct
13 Correct 430 ms 392 KB Output is correct
14 Correct 417 ms 388 KB Output is correct
15 Correct 425 ms 392 KB Output is correct
16 Correct 417 ms 460 KB Output is correct
17 Correct 421 ms 392 KB Output is correct
18 Correct 341 ms 340 KB Output is correct
19 Correct 442 ms 392 KB Output is correct
20 Correct 453 ms 388 KB Output is correct
21 Correct 431 ms 392 KB Output is correct
22 Correct 429 ms 340 KB Output is correct
23 Incorrect 15 ms 4336 KB Output isn't correct
24 Halted 0 ms 0 KB -

Subtask #7
0.0 / 18.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 212 KB Output is correct
2 Correct 0 ms 212 KB Output is correct
3 Correct 0 ms 212 KB Output is correct
4 Correct 1 ms 212 KB Output is correct
5 Correct 2 ms 212 KB Output is correct
6 Correct 1 ms 212 KB Output is correct
7 Correct 1 ms 212 KB Output is correct
8 Correct 1 ms 212 KB Output is correct
9 Correct 1 ms 212 KB Output is correct
10 Correct 1 ms 212 KB Output is correct
11 Correct 1 ms 212 KB Output is correct
12 Correct 1 ms 212 KB Output is correct
13 Correct 430 ms 392 KB Output is correct
14 Correct 417 ms 388 KB Output is correct
15 Correct 425 ms 392 KB Output is correct
16 Correct 417 ms 460 KB Output is correct
17 Correct 421 ms 392 KB Output is correct
18 Correct 341 ms 340 KB Output is correct
19 Correct 442 ms 392 KB Output is correct
20 Correct 453 ms 388 KB Output is correct
21 Correct 431 ms 392 KB Output is correct
22 Correct 429 ms 340 KB Output is correct
23 Correct 82 ms 25816 KB Output is correct
24 Correct 83 ms 25804 KB Output is correct
25 Correct 45 ms 17920 KB Output is correct
26 Correct 78 ms 24872 KB Output is correct
27 Correct 81 ms 24904 KB Output is correct
28 Incorrect 47 ms 18388 KB Output isn't correct
29 Halted 0 ms 0 KB -