Submission #430990

#	Time	Username	Problem	Language	Result	Execution time	Memory
430990		8e7	Park (JOI17_park)	C++14	100 / 100	349 ms	836 KiB

park

#include "park.h"
//Challenge: Accepted
#include <iostream>
#include <vector>
#include <algorithm>
#include <utility>
#include <random>
#include <time.h>
#include <assert.h>
#include <unordered_map>
#include <ext/pb_ds/assoc_container.hpp> // Common file
#include <ext/pb_ds/tree_policy.hpp> // Including tree_order_statistics_node_update
using namespace std;
//using namespace __gnu_pbds;
void debug() {cout << endl;}
template <class T, class ...U> void debug(T a, U ... b) { cout << a << " "; debug(b...);}
template <class T> void pary(T l, T r) {
	while (l != r) {cout << *l << " ";l++;}
	cout << endl;
}
#define ll long long
#define ld long double
#define maxn 1405
#define mod 1000000007
#define pii pair<long long, long long>
#define ff first
#define ss second

static int que[maxn];
vector<pii> ed;
vector<int> adj[maxn], vert;
int ord[maxn], par[maxn];
bool found[maxn], mark[maxn];
int qcnt = 0, mode = 0;
int query(int a, int b) {
	if (a > b) swap(a, b);
	if (a == b || (que[a] == 0) || (que[b] == 0)) return 0;
	qcnt++;
	return Ask(a, b, que);
}
vector<int> chain(vector<int> v) {
	if (v.size() <= 3) return v;
	int piv = v[1 + rand() % (v.size() - 2)];
	vector<int> lef, rig;
	lef.push_back(v[0]), rig.push_back(piv);
	for (int i:v) que[i] = 1;
	que[piv] = 0;
	for (int i = 1;i < v.size() - 1;i++) {
		if (v[i] != piv && query(v[0], v[i])) lef.push_back(v[i]);
		else if (v[i] != piv) rig.push_back(v[i]);
	}
	lef.push_back(piv), rig.push_back(v.back());
	lef = chain(lef), rig = chain(rig);
	vector<int> ret = lef;
	for (int i = 1;i < rig.size();i++) ret.push_back(rig[i]);
	return ret;
}
int ti = 0;
void dfs(int n, int par) {
	ord[ti++] = n;	
	for (int v:adj[n]) {
		if (v != par && !mark[v]) {
			dfs(v, n);
		}
	}
}
int tot;
int search(int ini, int x) {
	ti = 0;
	dfs(ini, -1);
	int low = 0, up = ti;
	//pary(ord, ord + ti);
	while (low + 1< up) {
		int mid = (low + up) / 2;
		for (int i = 0;i < ti;i++) que[ord[i]] = 1;
		for (int i = mid;i < ti;i++) que[ord[i]] = 0;
		if (query(x, ord[0])) up = mid;
		else low = mid;
	}
	return ord[low];
}
void getpath(vector<int> cand, vector<int> & ret, int x, int y) {
	if (cand.size() == 0) return;
	for (int i:cand) que[i] = 0; 
	bool res = query(x, y);
	if (res) {
		return;
	} else {
		for (int i:cand) que[i] = 1;
		if (cand.size() == 1) {
			ret.push_back(cand[0]);
			return;
		} else {
			vector<int> lef, rig;
			for (int i = 0;i < cand.size();i++) {
				if (i < cand.size() / 2) lef.push_back(cand[i]);
				else rig.push_back(cand[i]);
			}
			getpath(lef, ret, x, y), getpath(rig, ret, x, y);
		}
	}
}
void solve(int x, vector<int> v) {
	if (v.size() == 0) return;
	for (int i = 0;i < tot;i++) que[i] = 0;
	for (int i:v) que[i] = 1, mark[i] = 0;
	//pary(v.begin(), v.end());
	que[x] = 1;
	if (!query(x, v[0])) return;
	int y = search(v[0], x);
	//debug(x, y);
	ed.push_back({x, y});
	vector<vector<int> > rec;
	mark[y] = 1;
	for (int v:adj[y]) {
		if (mark[v] || v == x) continue;
		ti = 0, dfs(v, y);	
		vector<int> comp;
		for (int i = 0;i < ti;i++) comp.push_back(ord[i]);
		rec.push_back(comp);
	}
	for (auto i:rec) {
		solve(x, i);
	}
}
void Detect(int T, int N) {
	tot = N;
	if (T == 1) {
		for (int i = 0;i < N;i++) {
			for (int j = i + 1;j < N;j++) {
				que[i] = 1, que[j] = 1;
				if (query(i, j)) Answer(i, j);
				que[i] = 0, que[j] = 0;
			}
		}
		return;
	}
	srand(time(NULL));
	for (int i = 0;i < N;i++) vert.push_back(i);
	random_shuffle(vert.begin(), vert.end());
	found[vert[0]] = 1;
	for (int i = 1;i < N;i++) {
		if (found[vert[i]]) continue;
		for (int j = 0;j < N;j++) que[j] = 1;
		int anc = search(vert[0], vert[i]);	
		for (int j = 0;j < N;j++) que[j] = 0;
		vector<int> cand, path;
		for (int j = 0;j < N;j++) {
			if (!found[vert[j]] && j != i) cand.push_back(vert[j]), que[vert[j]] = 1;
		}
		que[vert[i]] = 1, que[anc] = 1;
		path.push_back(vert[i]);
		getpath(cand, path, vert[i], anc);
		path.push_back(anc);
		path = chain(path);
		for (int j:path) found[j] = 1;
		for (int j = 0;j < path.size() - 1;j++) {
			ed.push_back({path[j], path[j + 1]});
			adj[path[j]].push_back(path[j + 1]);
			adj[path[j + 1]].push_back(path[j]);
			par[path[j]] = path[j + 1];
		}	
	}
	par[vert[0]] = -1;
	ti = 0;
	dfs(vert[0], -1);
	vector<int> rev;
	for (int i = 0;i < N;i++) rev.push_back(ord[i]);
	reverse(rev.begin(), rev.end());
	for (int i = 0;i < N - 1;i++) {
		vector<int> sub;
		for (int j = i + 1;j < N;j++) {
			sub.push_back(rev[j]);
		}	
		for (int j = 0;j < N;j++) mark[j] = 1;
		//debug(49, rev[i], par[rev[i]]);
		solve(rev[i], sub);
	}
	//assert(ed.size() == N - 1);
	sort(ed.begin(), ed.end());
	ed.resize(int(unique(ed.begin(), ed.end()) - ed.begin()));
	for (auto i:ed) {
		if (i.ff > i.ss) swap(i.ff, i.ss);
		//debug(i.ff, i.ss);
		Answer(i.ff, i.ss);
	}
}
/*

4
10 14
0 1
0 2
0 5
1 2
1 3
1 5
2 4
2 6
2 7
3 6
3 9
5 9
7 8
7 9

4
8 7
0 1
0 2
0 3
0 4
0 5
0 6
0 7
*/

Compilation message (stderr)

park.cpp: In function 'std::vector<int> chain(std::vector<int>)':
park.cpp:48:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   48 |  for (int i = 1;i < v.size() - 1;i++) {
      |                 ~~^~~~~~~~~~~~~~
park.cpp:55:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   55 |  for (int i = 1;i < rig.size();i++) ret.push_back(rig[i]);
      |                 ~~^~~~~~~~~~~~
park.cpp: In function 'void getpath(std::vector<int>, std::vector<int>&, int, int)':
park.cpp:95:21: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   95 |    for (int i = 0;i < cand.size();i++) {
      |                   ~~^~~~~~~~~~~~~
park.cpp:96:11: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   96 |     if (i < cand.size() / 2) lef.push_back(cand[i]);
      |         ~~^~~~~~~~~~~~~~~~~
park.cpp: In function 'void Detect(int, int)':
park.cpp:157:20: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  157 |   for (int j = 0;j < path.size() - 1;j++) {
      |                  ~~^~~~~~~~~~~~~~~~~

• Subtask 1: 10 / 10
• Subtask 2: 10 / 10
• Subtask 3: 27 / 27
• Subtask 4: 30 / 30
• Subtask 5: 23 / 23