Submission #671513

#	Time	Username	Problem	Language	Result	Execution time	Memory
671513		user149	Easter Eggs (info1cup17_eastereggs)	C++14	0 / 100	1 ms	336 KiB

eastereggs

#include<bits/stdc++.h>
#include "grader.h"
using namespace std;

using pii=pair<int,int>;

int N;
vector<int> adjlist[555];

bool seen[555];
vector<int> preorder={-1};

void init(){
    fill(seen,seen+555,0);
    fill(adjlist,adjlist+555,(vector<int>){});
    preorder={-1};
}

void dfs(int node){
    seen[node]=1;
    preorder.push_back(node);

    for(int child:adjlist[node]){
        if(!seen[child]) dfs(child);
    }
}

int bsearch(){
    int lo=1;
    int hi=N;

    int prefix_sz=0;
    vector<int> query_vector={1}; // always a prefix [1..i]

    while(lo!=hi){
        int mid=(lo+hi)/2;
        while(query_vector.size()-1>lo) query_vector.pop_back();

        for(int i=lo+1;i<=mid;i++){
            query_vector.push_back(preorder[i]);
        }

        if(query(query_vector)) hi=mid;
        else lo=mid+1;
    }

    return lo;
}

int findEgg(int _N, vector<pii> edges){
    N=_N;
    init();
    for(pii i:edges){
        int a,b;
        tie(a,b)=i;
        adjlist[a].push_back(b);
        adjlist[b].push_back(a);
    }
    dfs(1);

    // return bsearch();
    return 0;
}

Compilation message (stderr)

eastereggs.cpp: In function 'int bsearch()':
eastereggs.cpp:37:36: warning: comparison of integer expressions of different signedness: 'std::vector<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   37 |         while(query_vector.size()-1>lo) query_vector.pop_back();
      |               ~~~~~~~~~~~~~~~~~~~~~^~~
eastereggs.cpp:32:9: warning: unused variable 'prefix_sz' [-Wunused-variable]
   32 |     int prefix_sz=0;
      |         ^~~~~~~~~

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