Submission #448592

#	Time	Username	Problem	Language	Result	Execution time	Memory
448592		JooDdae	Chameleon's Love (JOI20_chameleon)	C++17	100 / 100	163 ms	656 KiB

chameleon

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

int nxt[1010];
bool chk[1010];
vector<int> v[1010];

void addEdge(int a, int b){
    v[a].push_back(b), v[b].push_back(a);
}

int find_next(const int u, const vector<int> &q){
    if(q.empty() || v[u].size() == 3) return 0;

    vector<int> Q2(1, u);
    for(auto x : q) Q2.push_back(x);
    if(Query(Q2) == Q2.size()) return 0;

    int L = 0, R = q.size()-1;
    while(L <= R){
        int M = (L+R)/2;

        vector<int> Q(1, u);
        for(int i=0;i<=M;i++) Q.push_back(q[i]);

        if(Query(Q) == Q.size()) L = M+1;
        else R = M-1;
    }

    if(L == q.size()) return 0;

    addEdge(u, q[R+1]);
    return q[R+1];
}

void compress(set<int> &s){
    for(auto it = s.begin(); it != s.end(); ){
        if(v[*it].size() == 3) it = s.erase(it);
        else it = next(it);
    }
}

void Solve(int N) {
    set<int> s1, s2;

    for(int i=1;i<=2*N;i++){
        compress(s1), compress(s2);
        vector<int> q1(s1.begin(), s1.end()), q2(s2.begin(), s2.end());

        int k = 0;
        while(k = find_next(i, q1)){
            while(!q1.empty() && *q1.begin() <= k) q1.erase(q1.begin());
        }
        while(k = find_next(i, q2)){
            while(!q2.empty() && *q2.begin() <= k) q2.erase(q2.begin());
        }

        vector<int> chk2(2*N+1), g, b;
        queue<pair<int, int>> q; chk2[i] = 1; q.push({i, 0});
        while(!q.empty()){
            auto [u, c] = q.front(); q.pop();
            if(s1.count(u)) s1.erase(u);
            if(s2.count(u)) s2.erase(u);
            (c ? b : g).push_back(u);
            for(auto x : v[u]) if(!chk2[x]) chk2[x] = 1, q.push({x, !c});
        }

        for(auto x : g) s1.insert(x);
        for(auto x : b) s2.insert(x);
    }

    // for(int i=1;i<=2*N;i++){
    //     printf("[%d] :",i);
    //     for(int x : v[i]) printf(" %d",x);
    //     puts("");
    // }
    // ---------------------------------------- don't touch line -----------------------------------------


    for(int i=1;i<=2*N;i++) if(!chk[i])
        {if(v[i].size() == 1){
            chk[i] = chk[v[i][0]] = 1, Answer(i, v[i][0]);
            continue;
        }

        int &A = v[i][0], &B = v[i][1], &C = v[i][2];
        if(Query({i, B, C}) == 1) swap(A, C);
        else if(Query({i, A, C}) == 1) swap(B, C);
        nxt[i] = C, v[i].pop_back();
    }

    for(int i=1;i<=2*N;i++) if(!chk[i]){
        int x = (chk[v[i][1]] || nxt[v[i][1]] == i ? v[i][0] : v[i][1]);
        chk[i] = chk[x] = 1, Answer(i, x);
    }
}

Compilation message (stderr)

chameleon.cpp: In function 'int find_next(int, const std::vector<int>&)':
chameleon.cpp:18:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   18 |     if(Query(Q2) == Q2.size()) return 0;
      |        ~~~~~~~~~~^~~~~~~~~~~~
chameleon.cpp:27:21: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   27 |         if(Query(Q) == Q.size()) L = M+1;
      |            ~~~~~~~~~^~~~~~~~~~~
chameleon.cpp:31:10: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   31 |     if(L == q.size()) return 0;
      |        ~~^~~~~~~~~~~
chameleon.cpp: In function 'void Solve(int)':
chameleon.cpp:52:17: warning: suggest parentheses around assignment used as truth value [-Wparentheses]
   52 |         while(k = find_next(i, q1)){
      |               ~~^~~~~~~~~~~~~~~~~~
chameleon.cpp:55:17: warning: suggest parentheses around assignment used as truth value [-Wparentheses]
   55 |         while(k = find_next(i, q2)){
      |               ~~^~~~~~~~~~~~~~~~~~

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