제출 #288914

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
288914		andreiomd	Easter Eggs (info1cup17_eastereggs)	C++11	100 / 100	22 ms	416 KiB

eastereggs

#include <vector>
#include "grader.h"

using namespace std;

typedef pair < int, int > PII;

const int NMAX = ((1 << 9) + 5);
vector < int > G[NMAX];

vector < int > List;

inline void Reset (int n)
{
    for(int i = 1; i <= n; ++i)
        if(!G[i].empty())
            G[i].clear();

    if(!List.empty())
        List.clear();

    return;
}

inline void Add_Edge (int X, int Y)
{
    G[X].push_back(Y), G[Y].push_back(X);

    return;
}

inline void DFS (int Node, int Father)
{
    List.push_back(Node);

    for(auto it : G[Node])
        if(it != Father)
            DFS(it, Node);

    return;
}

inline bool Ok (int pos)
{
    vector < int > qq;

    for(int i = 0; i <= (pos - 1); ++i)
        qq.push_back(List[i]);

    return query(qq);
}

int findEgg (int n, vector < PII > edges)
{
    Reset(n);

    for(auto it : edges)
        Add_Edge(it.first, it.second);

    int root = edges[0].first;

    DFS(root, -1);

    int Left = 1, Right = n;

    while(Left < Right)
    {
        int Mid = (Left + Right) >> 1;

        if(Ok(Mid))
            Right = Mid;
        else
            Left = Mid + 1;
    }

    return List[Left - 1];
}

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