Submission #272802

#	Time	Username	Problem	Language	Result	Execution time	Memory
272802		KayacanV	Easter Eggs (info1cup17_eastereggs)	C++14	100 / 100	26 ms	384 KiB

eastereggs

#include <bits/stdc++.h>
 
using namespace std;
 
const int nmax = (1 << 9) + 10;
 
bool query(vector < int > v);
 
int n, all[nmax];
vector < int > g[nmax];
 
void dfs(int node, int dad) {
    all[++n] = node;
    for (auto &it: g[node])
        if (it != dad) dfs(it, node);
}
 
bool do_query(int n) {
    vector < int > res;
    for (int i = 1; i <= n; ++i)
        res.push_back(all[i]);
    return query(res);
}
 
void clear_(int n) {
    for (int i = 1; i <= n; ++i)
        g[i].clear();
}
 
int findEgg(int dim, vector < pair < int, int > > edges) {
    clear_(dim);
    for (int i = 0; i < dim - 1; ++i) {
        int x, y; tie(x, y) = edges[i];
        g[x].push_back(y); g[y].push_back(x);
    }
 
    n = 0; dfs(1, 0);
 
    int left = 1; int right = n - 1; int res = n;
    while (left <= right) {
        int mid = left + (right - left) / 2;
        if (do_query(mid) == 1)
            res = mid, right = mid - 1;
        else left = mid + 1;
    }
 
    res = all[res];
    return res;
}

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