Submission #201313

#	Time	Username	Problem	Language	Result	Execution time	Memory
201313		dimash241	Meetings (JOI19_meetings)	C++17	29 / 100	3085 ms	1672 KiB

meetings

//#pragma GCC target("avx2")
//#pragma GCC optimize("O3")

//# include <x86intrin.h>
#include "meetings.h"

# include <bits/stdc++.h>

# include <ext/pb_ds/assoc_container.hpp>
# include <ext/pb_ds/tree_policy.hpp>

using namespace __gnu_pbds;
using namespace std;
 
template<typename T> using ordered_set = tree <T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;

#define _USE_MATH_DEFINES_
#define ll long long
#define ld long double
#define Accepted 0
#define pb push_back
#define mp make_pair
#define sz(x) (int)(x.size())
#define every(x) x.begin(),x.end()
#define F first
#define S second
#define lb lower_bound
#define ub upper_bound
#define For(i,x,y)  for (ll i = x; i <= y; i ++) 
#define FOr(i,x,y)  for (ll i = x; i >= y; i --)
#define SpeedForce ios_base::sync_with_stdio(0), cin.tie(0), cout.tie(0)
// ROAD to...                                                                                                                                                                                                                Red

inline void Input_Output () {
	//freopen(".in", "r", stdin);
   //freopen(".out", "w", stdout);
}

const int dx[] = {-1, 0, 1, 0};
const int dy[] = {0, -1, 0, 1};
 
int n, m, k;
vector < int > g[2020];
int deg[2020];
int u[2020];

mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());

void Bridge (int, int);
int Query (int, int, int);
vector < pair < int, int > > v;

void PrintOut(int a, int b) {
	if (a > b) swap(a, b);
	v.pb(mp(a, b));
	if (sz(v) == n) {
		for (auto it : v)
			cout << it.F << ' ' << it.S << '\n';
		exit(0);
	}
	Bridge(a, b);
}

void reduce (vector < int > &v) {
	sort(every(v));
	v.resize(unique(every(v)) - v.begin());
	random_shuffle(every(v));
}


void go (int v) {
	u[v] = 1;
	for (auto to : g[v]) deg[to]--;
	for (auto to : g[v]) if (deg[to] == 0 && !u[to]) {
		PrintOut(v, to);
		go(to);
	}
	
}

void Solve(int N) {
	n = N;
	vector < int > p(n, 0);
	for (int i = 0; i < n; i ++) {
		g[i].clear();
		deg[i] = 0;
		u[i] = 0;
		p[i] = i;
	}  	

	for (int i = 1; i < n; ++i) {
		g[0].push_back(i);
		for (int j = i + 1; j < n; ++j) {
			int x = Query(0, i, j);
			if (x != j) g[x].pb(j);
			if (x != i) g[x].pb(i);
		}
	}

	for (int i = 0; i < n; i ++) {
		reduce(g[i]);
		for (auto j : g[i])
			++deg[j];
	}

	go(p[0]);
}

/*
namespace {

const int MAX_N = 2000;
const int MAX_CALLS = 100000;

void WrongAnswer(int code) {
  printf("Wrong Answer [%d]\n", code);
  exit(0);
}

int N, num_calls;
std::vector<int> graph[MAX_N];
std::set<std::pair<int, int>> edges, edges_reported;

int weight[MAX_N];

bool Visit(int p, int e, int rt = -1) {
  if (p == e) {
    ++weight[p];
    return true;
  }
  for (int q : graph[p]) {
    if (q != rt) {
      if (Visit(q, e, p)) {
        ++weight[p];
        return true;
      }
    }
  }
  return false;
}

}  // namespace

int Query(int u, int v, int w) {
  if (!(0 <= u && u <= N - 1 && 0 <= v && v <= N - 1 && 0 <= w && w <= N - 1 &&
        u != v && u != w && v != w)) {
    WrongAnswer(1);
  }
  if (++num_calls > MAX_CALLS) {
    WrongAnswer(2);
  }
  std::fill(weight, weight + N, 0);
  Visit(u, v);
  Visit(u, w);
  Visit(v, w);
  for (int x = 0; x < N; ++x) {
    if (weight[x] == 3) {
      return x;
    }
  }
  printf("Error: the input may be invalid\n");
  exit(0);
}

void Bridge(int u, int v) {
  if (!(0 <= u && u < v && v <= N - 1)) {
    WrongAnswer(3);
  }
  if (!(edges.count(std::make_pair(u, v)) >= 1)) {
    WrongAnswer(4);
  }
  if (!(edges_reported.count(std::make_pair(u, v)) == 0)) {
    WrongAnswer(5);
  }
  edges_reported.insert(std::make_pair(u, v));
}

int main() {
  if (scanf("%d", &N) != 1) {
    fprintf(stderr, "Error while reading input\n");
    exit(1);
  }
  for (int i = 0; i < N - 1; ++i) {
    int u, v;
    if (scanf("%d%d", &u, &v) != 2) {
      fprintf(stderr, "Error while reading input\n");
      exit(1);
    }
    graph[u].push_back(v);
    graph[v].push_back(u);
    edges.insert(std::make_pair(u, v));
  }

  num_calls = 0;
  Solve(N);
  if (edges_reported.size() != static_cast<size_t>(N - 1)) {
    WrongAnswer(6);
  }
  printf("Accepted: %d\n", num_calls);
  return 0;
}

// B...a   */

• Subtask 1: 7 / 7
• Subtask 2: 10 / 10
• Subtask 3: 12 / 12
• Subtask 4: 0 / 71