Submission #389315

#	Time	Username	Problem	Language	Result	Execution time	Memory
389315		balbit	Easter Eggs (info1cup17_eastereggs)	C++14	100 / 100	32 ms	456 KiB

eastereggs

#include <bits/stdc++.h>
#ifndef BALBIT
#include "grader.h"
#endif

using namespace std;

#define ll long long
#define pii pair<int, int>
#define f first
#define s second

#define REP(i,n) for (int i = 0; i<n; ++i)
#define REP1(i,n) for (int i = 1; i<=n; ++i)
#define SZ(x) (int)((x).size())
#define ALL(x) (x).begin(), (x).end()
#define pb push_back

#ifdef BALBIT
#define bug(...) cerr<<"#"<<__LINE__<<": "<<#__VA_ARGS__<<"- ", _do(__VA_ARGS__)
template<typename T> void _do(T && x) {cerr<<x<<endl;}
template<typename T, typename ...S> void _do(T && x, S && ...y) {cerr<<x<<", "; _do(y...);}
#else
#define bug(...)
#define endl '\n'
#endif // BALBITs

namespace {
    const int maxn = 600;
    vector<int> g[maxn];
    bool maybe[maxn];

    int need = 0;

    vector<int> ord;
    void dfs(int v, int p) {
        ord.pb(v);
        for (int u: g[v]) {
            if (u != p) {
                dfs(u,v);
            }
        }
    }

}

#ifdef BALBIT
bool query(vector<int> rr) {
    for (int x : rr) cout<<x<<' ';
    cout<<endl;
    bug("??");
    int y; cin>>y;
    return y;
}
#endif // BALBIT

int findEgg (int n, vector < pair < int, int > > bridges)
{
//    return 1;
//    if (query({n})) return 1;
//    return n;
    REP1(i,n) g[i].clear();
    for (pii p: bridges) {
        g[p.f].pb(p.s);
        g[p.s].pb(p.f);
    }
    fill(maybe, maybe+n+1,1);
    ord.clear();
    dfs(1, -1);
//    return 1;
    int left = n;
    int quers = 0;
    while (left > 1) {
        need=left/2;
        vector<int> tk;
        vector<int> tkg;
        REP(i,n) {
            int v = ord[i];
            if (maybe[v]) {
                --need;
                tkg.pb(v);
            }
            tk.pb(v);
            if (need == 0) break;
        }
        sort(ALL(tk));
        if (query(tk)) {
            left = left/2;
            fill(maybe, maybe+n+1, 0);
            for (int y : tkg) maybe[y] = 1;
        }else{
            left = left - left/2;
            for (int y : tk) maybe[y] = 0;
        }
//        ++quers;
//        if(quers > 10) while (1);
    }
//    while (1);
//    return 1;

    REP(i,n) {
        int v = ord[i];
        if (maybe[v]) {
//            if (!query({v})) while(1);
            return v;
        }
    }
    while (1);
    return 0;
//    assert(0);
}

#ifdef BALBIT
signed main(){
    ios::sync_with_stdio(0), cin.tie(0);
    bug(findEgg(5,  {{1, 2}, {1, 3}, {2,4}, {4,5}}));
}
#endif

Compilation message (stderr)

eastereggs.cpp: In function 'int findEgg(int, std::vector<std::pair<int, int> >)':
eastereggs.cpp:72:9: warning: unused variable 'quers' [-Wunused-variable]
   72 |     int quers = 0;
      |         ^~~~~

• Subtask 1: 40 / 40
• Subtask 2: 40 / 40
• Subtask 3: 20 / 20