Submission #1012480

#	Time	Username	Problem	Language	Result	Execution time	Memory
1012480		GrindMachine	Chameleon's Love (JOI20_chameleon)	C++17	100 / 100	41 ms	600 KiB

chameleon

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>

using namespace std;
using namespace __gnu_pbds;

template<typename T> using Tree = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
typedef long long int ll;
typedef long double ld;
typedef pair<int,int> pii;
typedef pair<ll,ll> pll;

#define fastio ios_base::sync_with_stdio(false); cin.tie(NULL)
#define pb push_back
#define endl '\n'
#define sz(a) (int)a.size()
#define setbits(x) __builtin_popcountll(x)
#define ff first
#define ss second
#define conts continue
#define ceil2(x,y) ((x+y-1)/(y))
#define all(a) a.begin(), a.end()
#define rall(a) a.rbegin(), a.rend()
#define yes cout << "Yes" << endl
#define no cout << "No" << endl

#define rep(i,n) for(int i = 0; i < n; ++i)
#define rep1(i,n) for(int i = 1; i <= n; ++i)
#define rev(i,s,e) for(int i = s; i >= e; --i)
#define trav(i,a) for(auto &i : a)

template<typename T>
void amin(T &a, T b) {
    a = min(a,b);
}

template<typename T>
void amax(T &a, T b) {
    a = max(a,b);
}

#ifdef LOCAL
#include "debug.h"
#else
#define debug(x) 42
#endif

/*

refs:
edi

*/

const int MOD = 1e9 + 7;
const int N = 1e3 + 5;
const int inf1 = int(1e9) + 5;
const ll inf2 = ll(1e18) + 5;

#include "chameleon.h"

namespace {

    int variable_example = 1;

}  // namespace

vector<int> adj[N];
vector<int> col(N);
vector<bool> vis(N);

void dfs1(int u){
    vis[u] = 1;
    int want = col[u]^1;
    trav(v,adj[u]){
        if(vis[v]){
            assert(col[v] == want);
        }
        else{
            col[v] = want;
            dfs1(v);
        }
    }
}

void Solve(int n) {
    // std::vector<int> p(3);
    // p[0] = 1;
    // p[1] = 2;
    // p[2] = 3;
    // variable_example = Query(p);
    // for (int i = 0; i < N; ++i) {
    //     Answer(i * 2 + 1, i * 2 + 2);
    // }

    auto is_edge = [&](vector<int> &v){
        return Query(v) != sz(v);
    };

    auto find_edges = [&](int u, vector<int> &nodes){
        int first_node = 0;
        while(true){
            int lo = first_node, hi = sz(nodes)-1;
            int first = -1;

            {
                vector<int> curr = {u};
                for(int j = first_node; j < sz(nodes); ++j){
                    curr.pb(nodes[j]);
                }

                if(!is_edge(curr)) break;
            }

            while(lo <= hi){
                int mid = (lo+hi) >> 1;
                vector<int> curr = {u};
                for(int j = first_node; j <= mid; ++j){
                    curr.pb(nodes[j]);                    
                }

                if(is_edge(curr)){
                    first = mid;
                    hi = mid-1;
                }
                else{
                    lo = mid+1;
                }
            }

            if(first == -1) break;

            int v = nodes[first];
            adj[u].pb(v), adj[v].pb(u);

            first_node = first+1;
        }
    };

    for(int i = 2; i <= 2*n; ++i){
        rep1(j,i-1){
            vis[j] = 0;
            col[j] = 0;
        }

        rep1(j,i-1){
            if(vis[j]) conts;
            dfs1(j);
        }

        vector<int> v1,v2;
        rep1(j,i-1){
            if(!col[j]) v1.pb(j);
            else v2.pb(j);
        }

        find_edges(i,v1);
        find_edges(i,v2);
    }

    vector<pii> ans;
    vector<bool> done(2*n+5);

    rep1(i,2*n){
        if(done[i]) conts;
        if(sz(adj[i]) == 1){
            int j = adj[i][0];
            ans.pb({i,j});
            done[i] = done[j] = 1;
        }
    }

    rep1(i,2*n){
        if(done[i]) conts;
        int x = adj[i].back();

        if(sz(adj[i]) == 1){
            ans.pb({i,x});
            done[i] = done[x] = 1;
            conts;
        }

        rep(ind,sz(adj[i])-1){
            int j = adj[i][ind];
            if(done[j]) conts;

            int cnt = 0;

            trav(k,adj[i]){
                if(k == i or k == j) conts;
                int res = Query({i,j,k});
                if(res == 1){
                    cnt++;
                }
            }

            if(cnt == 0) conts;

            trav(k,adj[j]){
                if(k == i or k == j) conts;
                int res = Query({i,j,k});
                if(res == 1){
                    cnt++;
                }
            }

            if(cnt == 2){
                x = j;
                break;
            }
        }

        assert(x != -1);

        ans.pb({i,x});
        done[i] = done[x] = 1;
    }

    for(auto [i,j] : ans){
        Answer(i,j);
    }
}

Compilation message (stderr)

chameleon.cpp:65:9: warning: '{anonymous}::variable_example' defined but not used [-Wunused-variable]
   65 |     int variable_example = 1;
      |         ^~~~~~~~~~~~~~~~

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