Submission #156809

#	Time	Username	Problem	Language	Result	Execution time	Memory
156809		popovicirobert	Meetings (JOI19_meetings)	C++14	100 / 100	1212 ms	1016 KiB

meetings

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

using namespace std;

inline void myBridge(int x, int y) {
	if(x > y) swap(x, y);
	//cerr << x << " " <<  y << "\n";
	Bridge(x, y);
}

void solve(vector <int> &nodes, int par) {
	int n = nodes.size();
	if(n == 1) {
		myBridge(par, nodes[0]);
		n--;
	}
	if(n == 0) return ;

	vector < pair <int, int> > arr;
	vector <int> path;
	int nod = nodes[rand() % n];
	for(auto it : nodes) {
		if(it == nod) continue;
		int cur = Query(par, it, nod);
		if(cur == it) {
			if(cur != par && cur != nod)
				path.push_back(cur);
		}
		else {
			arr.push_back({cur, it});
		}
	}
	sort(path.begin(), path.end());
	path.resize(unique(path.begin(), path.end()) - path.begin());

	sort(arr.begin(), arr.end());

	/*cerr << par << " " << nod << "\n";
	for(auto it : arr) {
		cerr << it.second << " ";
	}
	cerr << "\n";*/

	if(path.empty()) {
		myBridge(par, nod);
	}
	else {
		sort(path.begin(), path.end(), [&](const int &x, const int &y) {
					return Query(par, x, y) == x;
			});
		myBridge(par, path[0]);
		for(int i = 0; i + 1 < path.size(); i++) {
			myBridge(path[i], path[i + 1]);
		}
		myBridge(path.back(), nod);
	}
	
	int i = 0;
	while(i < arr.size()) {
		vector <int> aux;
		int j = i;
		while(j < arr.size() && arr[i].first == arr[j].first) {
			aux.push_back(arr[j].second);
			j++;
		}
		solve(aux, arr[i].first);
		//cerr << j << " " << arr.size() << "\n";
		i = j;
	}
}

void Solve(int n) {
	srand(time(NULL));
	vector <int> nodes(n - 1);
	iota(nodes.begin(), nodes.end(), 1);
	solve(nodes, 0);
}

Compilation message (stderr)

meetings.cpp: In function 'void solve(std::vector<int>&, int)':
meetings.cpp:53:24: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for(int i = 0; i + 1 < path.size(); i++) {
                  ~~~~~~^~~~~~~~~~~~~
meetings.cpp:60:10: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  while(i < arr.size()) {
        ~~^~~~~~~~~~~~
meetings.cpp:63:11: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   while(j < arr.size() && arr[i].first == arr[j].first) {
         ~~^~~~~~~~~~~~

• Subtask 1: 7 / 7
• Subtask 2: 10 / 10
• Subtask 3: 12 / 12
• Subtask 4: 71 / 71