Submission #583689

#	Time	Username	Problem	Language	Result	Execution time	Memory
583689		KoD	Xoractive (IZhO19_xoractive)	C++17	100 / 100	8 ms	516 KiB

Xoractive

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

using ll = long long;
using std::vector;
using std::array;
using std::pair;
using std::tuple;

template <class T>
constexpr T infty = std::numeric_limits<T>::max() / 2;

vector<int> guess(int N) {
    vector<int> ans(N);
    ans[0] = ask(1);
    const auto calc = [&](vector<int> pos) -> std::set<int> {
        if (pos.empty()) {
            return {};
        }
        for (auto& x : pos) {
            x += 1;
        }
        std::map<int, int> count;
        for (const int x : get_pairwise_xor(pos)) {
            count[x] -= 1;
        }
        pos.push_back(1);
        for (const int x : get_pairwise_xor(pos)) {
            count[x] += 1;
        }
        std::set<int> ret;
        for (const auto& [x, c] : count) {
            if (c - (x == 0) > 0) {
                ret.insert(x ^ ans[0]);
            } 
        }
        return ret;
    };
    const int LOG = 7;
    array<std::set<int>, LOG> set = {};
    for (int k = 0; k < LOG; ++k) {
        vector<int> pos;
        for (int i = 0; i < N; ++i) {
            if (i >> k & 1) {
                pos.push_back(i);
            }
        }
        set[k] = calc(pos);
    }
    for (int i = 1; i < N; ++i) {
        std::set<int> add, del;
        for (int k = 0; k < LOG; ++k) {
            if (i >> k & 1) {
                if (add.empty()) {
                    add = set[k];
                } else {
                    std::set<int> next;
                    for (const int x : set[k]) {
                        if (add.find(x) != add.end()) {
                            next.insert(x);
                        }
                    }
                    add = std::move(next);
                }
            } else {
                for (const int x : set[k]) {
                    del.insert(x);
                }
            }
        }
        for (const int x : del) {
            add.erase(x);
        }
        ans[i] = *add.begin();
    }
    return ans;
}

• Subtask 1: 6 / 6
• Subtask 2: 94 / 94