Submission #162816

#	Time	Username	Problem	Language	Result	Execution time	Memory
162816		Minnakhmetov	Highway Tolls (IOI18_highway)	C++14	12 / 100	387 ms	262144 KiB

highway

#include "highway.h"
#include <bits/stdc++.h>

using namespace std;

#define ll long long

struct E {
	int to, i;
};

const int N = 1e5 + 5;
vector<E> g[N], ord;

void dfs(int node, int anc) {
	for (E e : g[node]) {
		if (e.to != anc) {
			ord.push_back(e);
			dfs(e.to, node);
		}
	}
}

void find_pair(int n, vector<int> u, vector<int> v, int a, int b) {
	int m = u.size();

	for (int i = 0; i < m; i++) {
		g[u[i]].push_back({v[i], i});
		g[v[i]].push_back({u[i], i});
	}

	dfs(0, -1);

	// for (E e : ord) {
	// 	cout << e.to << " ";
	// }
	// cout << "\n";

	ll mx = ask(vector<int>(m, 1));

	int l = 0, r = ord.size();
	while (r - l > 1) {
		int p = (l + r) >> 1;
		vector<int> w(m);

		for (int i = 0; i < p; i++)
			w[ord[i].i] = 1;

		if (ask(w) == mx)
			r = p;
		else
			l = p;
	}

	answer(0, ord[r - 1].to);
}

• Subtask 1: 5 / 5
• Subtask 2: 7 / 7
• Subtask 3: 0 / 6
• Subtask 4: 0 / 33
• Subtask 5: 0 / 18
• Subtask 6: 0 / 31