Submission #484526

#	Time	Username	Problem	Language	Result	Execution time	Memory
484526		SansPapyrus683	Sirni (COCI17_sirni)	C++17	84 / 140	1029 ms	786436 KiB

sirni

#include <iostream>
#include <cassert>
#include <vector>
#include <algorithm>

using std::cout;
using std::endl;
using std::vector;
using std::pair;

class DisjointSets {
    private:
        vector<int> parents;
        vector<int> sizes;
    public:
        DisjointSets(int size) : parents(size), sizes(size, 1) {
            for (int i = 0; i < size; i++) {
                parents[i] = i;
            }
        }

        int get_ultimate(int n) {
            return parents[n] == n ? n : (parents[n] = get_ultimate(parents[n]));
        }

        bool link(int n1, int n2) {
            n1 = get_ultimate(n1);
            n2 = get_ultimate(n2);
            if (n1 == n2) {
                return false;
            }
            if (sizes[n1] < sizes[n2]) {
                std::swap(n1, n2);
            }
            sizes[n1] += sizes[n2];
            parents[n2] = n1;
            return true;
        }
};

/**
 * https://oj.uz/problem/view/COCI17_sirni
 * 4
 * 2
 * 6
 * 3
 * 11 should output 1
 */
int main() {
    int card_num;
    std::cin >> card_num;
    vector<int> cards(card_num);
    for (int& c : cards) {
        std::cin >> c;
        assert(c >= 1);
    }
    std::sort(cards.begin(), cards.end());
    // we can erase the dupes bc modding them with the original one = 0
    cards.erase(std::unique(cards.begin(), cards.end()), cards.end());

    int largest = *std::max_element(cards.begin(), cards.end());
    vector<int> next_largest(largest + 1, -1);
    for (int i = 0; i < cards.size(); i++) {
        next_largest[cards[i]] = i;
    }
    for (int c = largest - 1; c >= 0; c--) {
        // if this isn't assigned yet, assign it the previous one
        if (next_largest[c] == -1) {
            next_largest[c] = next_largest[c + 1];
        }
    }

    vector<pair<int, pair<int, int>>> good_links;
    for (int i = 0; i < cards.size() - 1; i++) {
        good_links.push_back({cards[i + 1] % cards[i], {i, i + 1}});
        for (int at = 2 * cards[i]; at <= largest; at += cards[i]) {
            int good_mod = next_largest[at];
            good_links.push_back({cards[good_mod] % cards[i], {i, good_mod}});
        }
    }

    std::sort(good_links.begin(), good_links.end());
    long long total_cost = 0;
    DisjointSets linked_cards(cards.size());
    for (const auto& [cost, to_link] : good_links) {
        total_cost += cost * linked_cards.link(to_link.first, to_link.second);
    }
    cout << total_cost << endl;
}

Compilation message (stderr)

sirni.cpp: In function 'int main()':
sirni.cpp:63:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   63 |     for (int i = 0; i < cards.size(); i++) {
      |                     ~~^~~~~~~~~~~~~~
sirni.cpp:74:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   74 |     for (int i = 0; i < cards.size() - 1; i++) {
      |                     ~~^~~~~~~~~~~~~~~~~~

• Subtask 1: 14 / 14
• Subtask 2: 0 / 14
• Subtask 3: 14 / 14
• Subtask 4: 14 / 14
• Subtask 5: 14 / 14
• Subtask 6: 14 / 14
• Subtask 7: 14 / 14
• Subtask 8: 0 / 14
• Subtask 9: 0 / 14
• Subtask 10: 0 / 14