Submission #1145844

#	Time	Username	Problem	Language	Result	Execution time	Memory
1145844		Ice_man	Easter Eggs (info1cup17_eastereggs)	C++20	100 / 100	8 ms	512 KiB

eastereggs

#include <iostream>
#include <vector>
#include "grader.h"
#define endl '\n'

using namespace std;

const int MAXN = 1024;

vector < int > e[MAXN];
vector < int > order;
int n;

void speed()
{
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
    cout.tie(nullptr);
}

void dfs(int node, int parent)
{
    order.push_back(node);

    for(int &nb : e[node])
    {
        if(nb == parent)
            continue;

        dfs(nb, node);
        //order.push_back(node);
    }
}

bool check(int mid)
{
    vector < int > q;
    q.clear();

    for(int i = 0 ; i <= mid ; i++)
    {
        q.push_back(order[i]);
    }

    return query(q);
}

int binarySearch()
{
    int L = 0, R = order.size() - 1, mid;
    int ans = 0;

    /**for(int i = 0; i < order.size(); i++)
        cout << i << " ";
    cout << endl;
    for(int i = 0; i < order.size(); i++)
        cout << order[i] << " ";
    cout << endl;*/

    while(L < R)
    {
        mid = (L + R) / 2;

        //cout << L << ' ' << R << ' ' << mid << " " << check(mid) <<endl;

        if(check(mid))
            R = mid;
        else
            L = mid + 1;
    }

    //cout << R << endl;
    return order[R];
}

void read(int N, vector < pair < int, int > > &bridges)
{
    n = N;

    for(pair <int , int>& i : bridges)
    {
        e[i.first].push_back(i.second);
        e[i.second].push_back(i.first);
    }
}

void clearMemory()
{
    for(int i = 0 ; i < MAXN ; i++)
    {
        e[i].clear();
    }
    order.clear();
}

int findEgg (int N, vector < pair < int, int > > bridges)
{
    read(N, bridges);

    dfs(1, -1);

    int ans = binarySearch();

    clearMemory();

    return ans;
}

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