Submission #834279

#	Time	Username	Problem	Language	Result	Execution time	Memory
834279		unnick	Arcade (NOI20_arcade)	C++14	65 / 100	1028 ms	34008 KiB

Arcade

#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;
#define ll long long
int main(){
    ios_base::sync_with_stdio(false);

    int n,m;
    cin >> n >> m;
    std::vector<ll> times;
    std::vector<ll> positions;

    for (int i = 0; i < m; i++) {
        ll tmp;
        cin >> tmp;
        times.push_back(tmp);
    }

    for (int i = 0; i < m; i++) {
        ll tmp;
        cin >> tmp;
        positions.push_back(tmp);
    }

    std::vector<int> idxes;

    for (int i = 0; i < m; i++) {
        idxes.push_back(i);
    }

    std::sort(idxes.begin(), idxes.end(), [times, positions](int ia, int ib){
        ll sa = times[ia] + positions[ia];
        ll sb = times[ib] + positions[ib];
        return sa == sb ? times[ia] < times[ib] : sa < sb;
    });

    std::vector<int> frontier;
    int num_arms = 0;

    for (int idx : idxes) {
        int selected_idx = -1;
        ll selected_score = 2100000000;
        for (int i = 0; i < num_arms; i++) {
            int idx2 = frontier[i];
            // // cant press a button twice with one hand
            // if (positions[idx] == positions[idx2] && times[idx] == times[idx2]) continue;
            // check if we can reach the button
            if (positions[idx]-positions[idx2] > times[idx]-times[idx2]) continue;
            // use the "least useful" hand
            if (selected_score < positions[idx2]-times[idx2]) continue;
            // cout << idx2 << " is better\n";
            selected_score = positions[idx2]-times[idx2];
            selected_idx = i;
        }
        if (selected_idx == -1) {
            // cout << "pushed" << "\n";
            frontier.push_back(idx);
            num_arms++;
        } else {
            // cout << "replaced " << selected_idx << "\n";
            frontier[selected_idx] = idx;
        }
        // cout << "frontier: ";
        // for (int i : frontier) {
        //     cout << i << " ";
        // }
        // cout << "\n";
    }

    cout << num_arms << '\n';
}

• Subtask 1: 7 / 7
• Subtask 2: 11 / 11
• Subtask 3: 12 / 12
• Subtask 4: 21 / 21
• Subtask 5: 14 / 14
• Subtask 6: 0 / 20
• Subtask 7: 0 / 15