Submission #502070

#	Time	Username	Problem	Language	Result	Execution time	Memory
502070		tengiz05	Monster Game (JOI21_monster)	C++17	100 / 100	111 ms	292 KiB

monster

#include "monster.h"
#include <bits/stdc++.h>

namespace {
    std::mt19937 rnd(std::chrono::steady_clock::now().time_since_epoch().count());
    std::vector<int> sort(std::vector<int> a) {
        if (a.size() == 1) {
            return a;
        }
        int m = a.size() / 2;
        std::shuffle(a.begin(), a.end(), rnd);
        std::vector<int> l(a.begin(), a.begin() + m), r(a.begin() + m, a.end());
        l = sort(l);
        r = sort(r);
        int i = 0, j = 0;
        for (int k = 0; k < int(a.size()); k++) {
            if (i == int(l.size())) {
                a[k] = r[j++];
            } else if (j == int(r.size())) {
                a[k] = l[i++];
            } else if (Query(l[i], r[j])) {
                a[k] = r[j++];
            } else {
                a[k] = l[i++];
            }
        }
        return a;
    }
    std::vector<int> slow(std::vector<int> a) {
        int n = a.size();
        std::vector res(n, std::vector<bool>(n));
        for (int i = 0; i < n; i++) {
            for (int j = i + 1; j < n; j++) {
                res[i][j] = Query(a[i], a[j]);
                res[j][i] = !res[i][j];
            }
        }
        std::vector<std::pair<int, int>> v;
        for (int i = 0; i < n; i++)
            v.emplace_back(std::accumulate(res[i].begin(), res[i].end(), 0), a[i]);
        std::sort(v.begin(), v.end());
        for (int i = 0; i < n; i++) {
            a[i] = v[i].second;
        }
        if (Query(a[1], a[0])) std::swap(a[1], a[0]);
        if (Query(a[n - 1], a[n - 2])) std::swap(a[n - 1], a[n - 2]);
        return a;
    }
}  // namespace

std::vector<int> Solve(int n) {
    std::vector<int> a(n);
    std::iota(a.begin(), a.end(), 0);
    a = sort(a);
    std::vector<int> s(a.begin(), a.begin() + std::min(n, 10));
    
    s = slow(s);
    
    int x = s[0];
    a.erase(std::find(a.begin(), a.end(), x));
    a.insert(a.begin(), x);
    
    for (int i = 1; i < n; i++) {
        int j = i;
        while (j < n && Query(a[j], x))
            j++;
        std::reverse(a.begin() + i, a.begin() + std::min(j + 1, n));
        i = j;
        x = a[i];
    }
    
    std::vector<int> ans(n);
    for (int i = 0; i < n; i++) {
        ans[a[i]] = i;
    }
    
    return ans;
}

• Subtask 1: 10 / 10
• Subtask 2: 15 / 15
• Subtask 3: 75 / 75