Submission #540740

#	Time	Username	Problem	Language	Result	Execution time	Memory
540740		two_sides	Chameleon's Love (JOI20_chameleon)	C++17	100 / 100	53 ms	544 KiB

chameleon

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

using namespace std;

bool check(vector<int> v, int x) {
    if (v.empty()) return false;
    v.push_back(x);
    return Query(v) != v.size();
}

void Solve(int n) {
    n = n * 2;
    vector<vector<int>> adj(n + 1);
    vector<int> col(n + 1), ans(n + 1);
    vector<int> pre(n + 1), nxt(n + 1);
    queue<int> que;
    for (int i = 1; i <= n; i++) {
        for (int j = 1; j < i; j++)
            col[j] = -1;
        for (int j = 1, u; j < i; j++) {
            if (col[j] >= 0) continue;
            que.push(j); col[j] = 0;
            while (que.size()) {
                u = que.front(); que.pop();
                for (int v : adj[u])
                    if (col[v] < 0) {
                        col[v] = 1 - col[u];
                        que.push(v);
                    }
            }
        }
        vector<int> half[2];
        for (int j = 1; j < i; j++)
            half[col[j]].push_back(j);
        for (int j = 0; j < 2; j++) {
            while (check(half[j], i)) {
                int l = 1, r = half[j].size();
                while (l < r) {
                    int m = (l + r) / 2;
                    if (check(vector<int>
                    (half[j].begin(),
                    half[j].begin() + m), i))
                        r = m;
                    else l = m + 1;
                }
                adj[i].push_back(half[j][l - 1]);
                adj[half[j][l - 1]].push_back(i);
                half[j].erase(half[j].begin(),
                half[j].begin() + l);
            }
        }
    }
    for (int i = 1; i <= n; i++) {
        if (adj[i].size() == 1) continue;
        while (Query({i, adj[i][0], adj[i][1]}) != 1)
            rotate(adj[i].begin(), adj[i].begin() + 1, adj[i].end());
        nxt[i] = adj[i][2]; pre[adj[i][2]] = i;
    }
    for (int i = 1; i <= n; i++) {
        if (adj[i].size() == 1) ans[i] = adj[i][0];
        else ans[i] = adj[i][0] + adj[i][1] + adj[i][2] - nxt[i] - pre[i];
        if (ans[i] > i) Answer(i, ans[i]);
    }
}

Compilation message (stderr)

chameleon.cpp: In function 'bool check(std::vector<int>, int)':
chameleon.cpp:9:21: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
    9 |     return Query(v) != v.size();
      |            ~~~~~~~~~^~~~~~~~~~~

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