Submission #985221

#	Time	Username	Problem	Language	Result	Execution time	Memory
985221		CrazyBotBoy	Sequence (APIO23_sequence)	C++17	11 / 100	2039 ms	27628 KiB

sequence

#include "sequence.h"
#include <vector>
#include <unordered_map>
#include <set>
#include <iostream>
#include <algorithm>
#include <map>
#include <queue>

using namespace std;

// Helper class to maintain the sliding window median
class SlidingWindowMedian {
public:
    void insert(int num) {
        if (maxHeap.empty() || num <= maxHeap.top()) {
            maxHeap.push(num);
        } else {
            minHeap.push(num);
        }
        balanceHeaps();
    }

    void erase(int num) {
        if (!maxHeap.empty() && num <= maxHeap.top()) {
            delayedDeletions[num]++;
            while (!maxHeap.empty() && delayedDeletions[maxHeap.top()]) {
                delayedDeletions[maxHeap.top()]--;
                maxHeap.pop();
            }
        } else {
            delayedDeletions[num]++;
            while (!minHeap.empty() && delayedDeletions[minHeap.top()]) {
                delayedDeletions[minHeap.top()]--;
                minHeap.pop();
            }
        }
        balanceHeaps();
    }

    int getMedian() {
        return maxHeap.top();
    }

private:
    priority_queue<int> maxHeap;
    priority_queue<int, vector<int>, greater<int>> minHeap;
    unordered_map<int, int> delayedDeletions;

    void balanceHeaps() {
        if (maxHeap.size() > minHeap.size() + 1) {
            minHeap.push(maxHeap.top());
            maxHeap.pop();
        } else if (minHeap.size() > maxHeap.size()) {
            maxHeap.push(minHeap.top());
            minHeap.pop();
        }
    }
};

int sequence(int N, vector<int> A) {
    int maxOccurrences = 0;

    for (int l = 0; l < N; ++l) {
        unordered_map<int, int> freq;
        SlidingWindowMedian swm;

        for (int r = l; r < N; ++r) {
            swm.insert(A[r]);
            freq[A[r]]++;

            int median = swm.getMedian();
            maxOccurrences = max(maxOccurrences, freq[median]);
        }
    }

    return maxOccurrences;
}

• Subtask 1: 11 / 11
• Subtask 2: 0 / 17
• Subtask 3: 0 / 7
• Subtask 4: 0 / 12
• Subtask 5: 0 / 13
• Subtask 6: 0 / 22
• Subtask 7: 0 / 18