Submission #294589

#	Time	Username	Problem	Language	Result	Execution time	Memory
294589		SeDunion	Highway Tolls (IOI18_highway)	C++14	0 / 100	124 ms	10560 KiB

highway

#include "highway.h"
#include <bits/stdc++.h>
using namespace std;
using ll = long long;

int M;
ll Ask (vector<int> v) {
	vector<int> w(M);
	for (int i : v) w[i] = 1;
	return ask (w);
}

const int N = 2e5;
vector<pair<int,int>> g[N], mb;

void dfs (int v, ll d, int p = -1) {
	for (auto [to, i] : g[v]) if (to != p) {
		if (d == 1) {
			mb.push_back ({to, i});
		} else {
			dfs (to, d-1, v);
		}
	}
}

void find_pair(int N, vector<int> U, vector<int> V, int A, int B) {
	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});
	}
	if (Ask({}) % A) while(1);
	ll dist = Ask ({}) / A;
	dfs (0, dist);
	if (mb.empty()) while(1);
	int l = 0, r = int(mb.size()) - 1;
	while (l < r) {
		int m = (l + r) >> 1;
		vector<int>now;
		for (int i = 0 ; i <= m ; ++ i) {
			now.push_back (mb[i].second);
		}
		if (Ask(now) > dist) {
			r = m;
		} else {
			l = m + 1;
		}
	}
	answer (0, mb[r].first);
}

Compilation message (stderr)

highway.cpp: In function 'void dfs(int, ll, int)':
highway.cpp:17:12: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   17 |  for (auto [to, i] : g[v]) if (to != p) {
      |            ^

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