Submission #920598

#	Time	Username	Problem	Language	Result	Execution time	Memory
920598		DON_F	Easter Eggs (info1cup17_eastereggs)	C++14	0 / 100	1 ms	500 KiB

eastereggs

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

using namespace std;
using ll = long long;
#define F first
#define S second

vector < vector < int > > g;
set < int > cur, sp;
vector < int > all, vis;
ll p;

void dfs(int u){
   if ((int) sp.size() == p){
      return;
   }
   all.push_back(u);
   if (cur.count(u)){
     sp.insert(u);
   }
   for (auto &i : g[u]){
     dfs(i);
   }
}

int findEgg (int n, vector < pair < int, int > > z){
    for (int i = 1; i <= n; ++i){
        cur.insert(i);
    }
    g = vector < vector < int > > (n + 1);
    ll lg = ceil(log2(n)), c = 0;
    for (int i = 0; i < n - 1; ++i){
        g[z[i].F].push_back(z[i].S);
    }
    while (cur.size() != 1 && lg){
        p = cur.size() / 2;
        for (int i = 1; i <= n; ++i){
            dfs(i);
            if ((int) sp.size() == p){
                break;
            }
            sp.clear();
            all.clear();
        }
        if (sp.size() != p)cout << -1;
        ll tmp = query(all);
        if (tmp){
           cur.clear();
           for (auto &i : sp){
              cur.insert(i);
           }
        }else{
           for (auto &i : sp){
             cur.erase(i);
           }
        }
        sp.clear();
        all.clear();
        lg--;
    }
    return *cur.begin();
}

Compilation message (stderr)

eastereggs.cpp: In function 'int findEgg(int, std::vector<std::pair<int, int> >)':
eastereggs.cpp:46:23: warning: comparison of integer expressions of different signedness: 'std::set<int>::size_type' {aka 'long unsigned int'} and 'll' {aka 'long long int'} [-Wsign-compare]
   46 |         if (sp.size() != p)cout << -1;
      |             ~~~~~~~~~~^~~~
eastereggs.cpp:32:28: warning: unused variable 'c' [-Wunused-variable]
   32 |     ll lg = ceil(log2(n)), c = 0;
      |                            ^

• Subtask 1: 0 / 40
• Subtask 2: 0 / 40
• Subtask 3: 0 / 20