Submission #591961

#	Time	Username	Problem	Language	Result	Execution time	Memory
591961		Jarif_Rahman	Chameleon's Love (JOI20_chameleon)	C++17	100 / 100	76 ms	720 KiB

chameleon

#include "chameleon.h"
#include <bits/stdc++.h>
#define pb push_back
#define f first
#define sc second
using namespace std;
typedef long long int ll;
typedef string str;

namespace {
    int query(vector<int> v){
        for(int &x: v) x++;
        return Query(v);
    }
    void answer(int a, int b){
        Answer(a+1, b+1);
    }

    int n;

    vector<vector<int>> v;
    set<pair<int, int>> s;
    vector<int> g[2];
    vector<int> color;

    void dfs(int nd, int c){
        color[nd] = c;
        g[c].pb(nd);
        c = 1-c;
        for(int x: v[nd]){
            if(color[x] == c) continue;
            else dfs(x, c);
        }
    }
    void make_groups(int m){
        color.assign(m+1, -1);
        g[0].clear();
        g[1].clear();
        for(int i = 0; i <= m; i++) if(color[i] == -1) dfs(i, 0);
    }

    void bs(int i, vector<int> sth){
        while(!sth.empty()){
            auto ss = sth;
            ss.pb(i);
            if(query(ss) == ss.size()) break;

            int l = 0, r = sth.size();
            while(l < r){
                int md = (l+r)/2;
                vector<int> ss(sth.begin(), sth.begin()+md+1);
                ss.pb(i);
                if(query(ss) == ss.size()) l = md+1;
                else r = md;
            }

            v[i].pb(sth[l]);
            v[sth[l]].pb(i);

            sth.erase(sth.begin()+l);
        }
    }
}

void Solve(int _n){
    n = _n;
    v.resize(2*n);

    for(int i = 0; i < 2*n; i++){
        bs(i, g[0]);
        bs(i, g[1]);
        make_groups(i);
    }

    for(int i = 0; i < 2*n; i++) for(int x: v[i]) s.insert({min(i, x), max(i, x)});

    for(int i = 0; i < 2*n; i++){
        if(v[i].size() < 3) continue;
        int a = v[i][0], b = v[i][1], c = v[i][2];
        int rm = -1;
        if(query({i, a, b}) == 1) rm = c;
        else if(query({i, a, c}) == 1) rm = b;
        else rm = a;
        if(s.find({min(i, rm), max(i, rm)}) != s.end()) s.erase({min(i, rm), max(i, rm)});
    }

    for(auto [a, b]: s) answer(a, b);
}

Compilation message (stderr)

chameleon.cpp: In function 'void {anonymous}::bs(int, std::vector<int>)':
chameleon.cpp:46:26: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   46 |             if(query(ss) == ss.size()) break;
      |                ~~~~~~~~~~^~~~~~~~~~~~
chameleon.cpp:53:30: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   53 |                 if(query(ss) == ss.size()) l = md+1;
      |                    ~~~~~~~~~~^~~~~~~~~~~~

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