Submission #1099671

#	Time	Username	Problem	Language	Result	Execution time	Memory
1099671		tuannm	Easter Eggs (info1cup17_eastereggs)	C++17	0 / 100	153 ms	131072 KiB

eastereggs

#include<bits/stdc++.h>
#include "grader.h"
#define ii pair<int, int>
#define fi first
#define se second
#define pb push_back
using namespace std;
const int maxN = 520;

vector<int> adj[maxN], dfs;

/*
bool isEgg[maxN];

bool query(vector<int> gg){
    for(int i : gg)
        if(isEgg[i])
            return true;

    return false;
}
*/

void DFS(int u = 1, int p = 0){
    dfs.pb(u);

    for(int v : adj[u]){
        if(v == p)
            continue;

        DFS(v, u);
    }

}

int findEgg(int N, vector<ii> bridges){
    for(auto [u, v] : bridges)
        adj[u].pb(v), adj[v].pb(u);

    DFS();

    int ans = 0, l = 0, r = N - 1;

    while(l <= r){
        int mid = l + r >> 1;

        if(query(vector<int> (dfs.begin(), dfs.begin() + mid)))
            ans = mid, r = mid - 1;
        else l = mid + 1;
    }

    return ans;
}

/*
mt19937 rd(chrono::steady_clock::now().time_since_epoch().count());

int Rand(int l, int r){
    return l + rd() % (r - l + 1);
}

int main(){
    for(int __ = 1; __ <= 100; ++__){
        int N = Rand(512, 512);

        vector<ii> bridges;

        for(int i = 2; i <= N; ++i)
            bridges.pb({i, Rand(1, i - 1)});

        for(int i = 1; i <= N; ++i)
            isEgg[i] = Rand(0, 1);

        int gg = Rand(1, N);
        isEgg[gg] = true;

        int u = findEgg(N, bridges);

        for(int i = 1; i <= N; ++i)
            adj[i].clear();

        if(!isEgg[u]){
            cout << "Wrong on test " << __ << ":\n";
            cout << N << "\n";
            for(auto [x, y] : bridges)
                cout << x << " " << y << "\n";

            for(int i = 1; i <= N; ++i)
                if(isEgg[i])
                    cout << i << " ";

            cout << "\nYour answer: " << u << ".\n";
            return 0;
        }

        for(int i = 1; i <= N; ++i)
            isEgg[i] = false;
    }

    cout << "OK.\n";
}
*/

Compilation message (stderr)

eastereggs.cpp: In function 'int findEgg(int, std::vector<std::pair<int, int> >)':
eastereggs.cpp:45:21: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   45 |         int mid = l + r >> 1;
      |                   ~~^~~

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