Submission #463672

#	Time	Username	Problem	Language	Result	Execution time	Memory
463672		tomsyd	Highway Tolls (IOI18_highway)	C++17	0 / 100	273 ms	262148 KiB

highway

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

vector<vector<int>> adj;
vector<int> nodes;

void dfs(int node, int prev){
	for (int i:adj[node]){
		if (i != prev){
			dfs(i,node);
		}
	}
	nodes.emplace_back(node);
}

void find_pair(int N, vector<int> U, vector<int> V, int A, int B) {
	int M = U.size();
	nodes.clear();
	adj = vector<vector<int>>(N);
	for (int i=0; i<M; ++i){
		adj[U[i]].emplace_back(V[i]);
		adj[V[i]].emplace_back(U[i]);
	}
	dfs(0,-1);
	vector<int> query;
	for (int i=0; i<N; ++i) query.emplace_back(1);
	int init = ask(query), crt = nodes[nodes.size()-1];
	for (int j=0; j<nodes.size()-1; ++j){
		query[nodes[j]] = 0;
		if (ask(query) != init){
			crt = nodes[j];
			break;
		}
		query[nodes[j]] = 1;
	}
	answer(crt,0);
}

Compilation message (stderr)

highway.cpp: In function 'void find_pair(int, std::vector<int>, std::vector<int>, int, int)':
highway.cpp:29:17: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   29 |  for (int j=0; j<nodes.size()-1; ++j){
      |                ~^~~~~~~~~~~~~~~

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