Submission #895367

#	Time	Username	Problem	Language	Result	Execution time	Memory
895367		box	Chameleon's Love (JOI20_chameleon)	C++17	40 / 100	24 ms	600 KiB

chameleon

#include <bits/stdc++.h>
#include "chameleon.h"
using namespace std;

#define ar array
#define sz(v) int(std::size(v))
using i64 = long long;
using vi = vector<int>;

const int MAXN = 505 * 2;

vi adj[MAXN];
int who[MAXN], nex[MAXN], pre[MAXN];

vi operator+(vi one, const vi two) {
    one.insert(end(one), begin(two), end(two));
    return one;
}
bool interesting(vi one) {
    return Query(one) != sz(one);
}

void Solve(int N) {
    if (N <= 50) {
        for (int i = 1; i <= N * 2; i++)
            for (int j = i + 1; j <= N * 2; j++)
                if (Query({i, j}) == 1) {
                    adj[i].push_back(j);
                    adj[j].push_back(i);
                }
    } else {
        vi base(N);
        iota(begin(base), end(base), 1);
        for (int i = N + 1; i <= N * 2; i++) {
            vi v = base;
            while (interesting(v + vi{{i}})) {
                int low = 0, hi = sz(v) - 1;
                while (low < hi) {
                    int m = (low + hi) / 2;
                    interesting(vi(begin(v), begin(v) + m + 1)) ? hi = m : low = m + 1;
                }
                adj[v[low]].push_back(i);
                adj[i].push_back(v[low]);
                v.erase(begin(v), begin(v) + low + 1);
            }
        }
    }
    for (int i = 1; i <= N * 2; i++) {
        assert(sz(adj[i]) == 1 || sz(adj[i]) == 3);
        if (sz(adj[i]) == 1) {
            who[i] = adj[i][0];
        } else {
            nex[i] = [&]() {
                if (Query({i, adj[i][0], adj[i][1]}) == 1) return adj[i][2];
                if (Query({i, adj[i][0], adj[i][2]}) == 1) return adj[i][1];
                return adj[i][0];
            }();
            pre[nex[i]] = i;
        }
    }
    for (int i = 1; i <= N * 2; i++) {
        if (!who[i]) {
            assert(sz(adj[i]) == 3);
            assert(pre[i] && nex[i]);
            who[i] = adj[i][0] ^ adj[i][1] ^ adj[i][2] ^ pre[i] ^ nex[i];
        }
        if (who[i] < i) Answer(who[i], i);
    }
}

• Subtask 1: 0 / 4
• Subtask 2: 20 / 20
• Subtask 3: 20 / 20
• Subtask 4: 0 / 20
• Subtask 5: 0 / 36