| # | Time | Username | Problem | Language | Result | Execution time | Memory |
|---|---|---|---|---|---|---|---|
| 561798 | timreizin | Meetings (JOI19_meetings) | C++17 | 0 ms | 0 KiB |
This submission is migrated from previous version of oj.uz, which used different machine for grading. This submission may have different result if resubmitted.
#pragma GCC optimize("Ofast,unroll-loops")
#pragma GCC target("avx2,bmi,bmi2,popcnt,lzcnt")
#include "meetings.h"
#include <random>
#include <vector>
#include <set>
#include <numeric>
#include <cassert>
using namespace std;
vector<vector<int>> adj;
mt19937 gen(random_device());
int find(vector<int> vertices, int pivot, set<int> path)
{
if (vertices.size() == 1) return vertices.front();
if (vertices.size() == 2)
{
//do
adj[vertices.front()].push_back(vertices.back());
adj[vertices.back()].push_back(vertices.front());
}
else
{
vector<bool> used(vertices.size());
int left = vertices.size();
int pivot = uniform_int_distribution<>(0, left - 1)(gen);
used[pivot] = true;
--left;
pivot = vertices[pivot];
while (left)
{
int p = uniform_int_distribution<>(1, left)(gen);
for (int i = 0; i < vertices.size(); ++i)
{
p -= !used[i];
if (!p)
{
--left;
used[i] = true;
p = vertices[i];
break;
}
}
vector<int> next{p};
set<int> path;
for (int i = 0; i < vertices.size(); ++i)
{
if (!used[i])
{
int r = Query(vertices[i], p, pivot);
if (r != pivot)
{
used[i] = true;
--left;
next.push_back(vertices[i]);
if (r == vertices[i]) path.insert(r);
}
}
}
int e = find(next, p, path);
adj[pivot].push_back(e);
adj[e].push_back(pivot);
}
}
int v = pivot;
while (!path.empty())
{
for (int u : adj[v])
{
if (path.find(u) != path.end())
{
path.erase(u);
v = u;
}
}
}
return v;
}
void Solve(int n)
{
adj.resize(n);
set<int> path;
vector<int> vertices(n);
iota(vertices.begin(), vertices.end(), 0);
find(vertices, 0, path);
for (int i = 0; i < n; ++i)
{
for (int u : adj[i])
{
if (i < u) Bridge(i, u);
}
}
}