Submission #448142

#	Time	Username	Problem	Language	Result	Execution time	Memory
448142		jhnah917	Chameleon's Love (JOI20_chameleon)	C++14	100 / 100	94 ms	1528 KiB

chameleon

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

namespace {
    int N, Match[1010], Color[1010];
    bool Love[1010][1010];
    vector<int> G[1010], Nodes[2];

    void Init(){
        memset(Match, -1, sizeof Match);
        memset(Color, -1, sizeof Color);
        memset(Love, 0, sizeof Love);
        for(int i=0; i<1010; i++) G[i].clear();
    }

    void DFS(int v, int color){
        Color[v] = color; Nodes[color].push_back(v);
        for(auto i : G[v]) if(Color[i] == -1) DFS(i, color^1);
    }

    bool HasEdge(vector<int> vec, int now){
        vec.push_back(now);
        return Query(vec) < vec.size();
    }

    int Search(const vector<int> &vec, int v){
        int l = 0, r = vec.size() - 1;
        while(l < r){
            int m = l + r >> 1;
            vector<int> now;
            for(int i=0; i<=m; i++) now.push_back(vec[i]);
            if(HasEdge(now, v)) r = m;
            else l = m + 1;
        }
        return r;
    }

    int Like(int v){
        int a = G[v][0], b = G[v][1], c = G[v][2];
        if(Query({ v, b, c }) == 1) return a;
        if(Query({ v, a, c }) == 1) return b;
        return c;
    }
}  // namespace

void Solve(int n){
    N = n + n; Init();
    for(int i=1; i<=N; i++){
        memset(Color, -1, sizeof Color);
        Nodes[0].clear(); Nodes[1].clear();
        for(int j=1; j<i; j++) if(Color[j] == -1) DFS(j, 0);

        for(int c=0; c<2; c++){
            while(HasEdge(Nodes[c], i)){
                auto j = Search(Nodes[c], i);
                G[i].push_back(Nodes[c][j]);
                G[Nodes[c][j]].push_back(i);
                Nodes[c].erase(Nodes[c].begin() + j);
            }
        }
    }

    for(int i=1; i<=N; i++){
        if(G[i].size() == 1){
            Match[i] = G[i][0];
            Match[G[i][0]] = i;
            continue;
        }
        int j = Like(i);
        Love[i][j] = Love[j][i] = true;
    }

    for(int i=1; i<=N; i++){
        if(Match[i] != -1) continue;
        for(auto j : G[i]) if(!Love[i][j]) Match[i] = j;
    }
    for(int i=1; i<=N; i++) if(i < Match[i]) Answer(i, Match[i]);
}

Compilation message (stderr)

chameleon.cpp: In function 'bool {anonymous}::HasEdge(std::vector<int>, int)':
chameleon.cpp:24:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   24 |         return Query(vec) < vec.size();
      |                ~~~~~~~~~~~^~~~~~~~~~~~
chameleon.cpp: In function 'int {anonymous}::Search(const std::vector<int>&, int)':
chameleon.cpp:30:23: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   30 |             int m = l + r >> 1;
      |                     ~~^~~

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