Submission #985217

#	Time	Username	Problem	Language	Result	Execution time	Memory
985217		CrazyBotBoy	Sequence (APIO23_sequence)	C++17	11 / 100	2065 ms	51120 KiB

sequence

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

using namespace std;

// Helper function to add element to the multiset and update the frequency map
void add_element(multiset<int>& lower, multiset<int>& upper, map<int, int>& freq, int element) {
    if (lower.empty() || element <= *lower.rbegin()) {
        lower.insert(element);
    } else {
        upper.insert(element);
    }

    // Balance the sets
    if (lower.size() > upper.size() + 1) {
        upper.insert(*lower.rbegin());
        lower.erase(prev(lower.end()));
    } else if (upper.size() > lower.size()) {
        lower.insert(*upper.begin());
        upper.erase(upper.begin());
    }

    // Update frequency
    freq[element]++;
}

// Helper function to remove element from the multiset and update the frequency map
void remove_element(multiset<int>& lower, multiset<int>& upper, map<int, int>& freq, int element) {
    if (lower.find(element) != lower.end()) {
        lower.erase(lower.find(element));
    } else {
        upper.erase(upper.find(element));
    }

    // Balance the sets
    if (lower.size() > upper.size() + 1) {
        upper.insert(*lower.rbegin());
        lower.erase(prev(lower.end()));
    } else if (upper.size() > lower.size()) {
        lower.insert(*upper.begin());
        upper.erase(upper.begin());
    }

    // Update frequency
    freq[element]--;
    if (freq[element] == 0) {
        freq.erase(element);
    }
}

// Function to get the median from the two balanced sets
int get_median(const multiset<int>& lower, const multiset<int>& upper) {
    return *lower.rbegin();
}

int sequence(int N, vector<int> A) {
    int maxOccurrences = 0;
    
    for (int l = 0; l < N; ++l) {
        multiset<int> lower, upper;
        map<int, int> freq;
        
        for (int r = l; r < N; ++r) {
            add_element(lower, upper, freq, A[r]);
            
            int median = get_median(lower, upper);
            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