Submission #429602

#	Time	Username	Problem	Language	Result	Execution time	Memory
429602		Kevin_Zhang_TW	Park (JOI17_park)	C++17	77 / 100	222 ms	776 KiB

park

#include <bits/stdc++.h>
using namespace std;
using ll = long long;
#define pb emplace_back
#define AI(i) begin(i), end(i)
template<class T> bool chmin(T &a, T b) { return b < a && (a = b, true); }
template<class T> bool chmax(T &a, T b) { return a < b && (a = b, true); }
#ifdef KEV
#define DE(args...) kout("[ " + string(#args) + " ] = ", args)
void kout() { cerr << endl; }
template<class T, class ...U> void kout(T a, U ...b) { cerr << a << ' ', kout(b...); }
template<class T> void debug(T l, T r) { while (l != r) cerr << *l << " \n"[next(l)==r], ++l; }
#else
#define DE(...) 0
#define debug(...) 0
#endif
#include "park.h"

const int MAX_N = 1400;
static int Place[1400];

int n;

int mrand(int l, int r) {
	static random_device rd;
	static mt19937 gen(rd());
	return uniform_int_distribution(l, r)(gen);
}

int qry_list(int a, int b, vector<int> go) {
	static int ok[MAX_N];
	fill(ok, ok + n, 0);
	for (int i : go) ok[i] = true;
	ok[a] = ok[b] = true;
	if (a > b) swap(a, b);
	return Ask(a, b, ok);
}
int qry_tf(int a, int b, vector<int> go) {
	static int ok[MAX_N];
	copy(AI(go), ok);
	if (a > b) swap(a, b);
	return Ask(a, b, ok);
}

void ans(int a, int b) {
	if (a > b) swap(a, b);
	Answer(a, b);
}
bool on_tree[MAX_N];
vector<int> edge[MAX_N];

vector<int> find_path(int a, int b) {
	vector<int> onpath(n);
	for (int i = 0;i < n;++i) if (!on_tree[i])
		onpath[i] = true;
	onpath[a] = onpath[b] = true;

	vector<int> allon;
	for (int i = 0;i < n;++i) if (i != a && i != b && onpath[i])
		allon.pb(i);

	function<void(vector<int>)> kick = [&](vector<int> all) {
		if (all.empty()) return;
		for (int x : all) onpath[x] = false;
		if (qry_tf(a, b, onpath)) return;
		for (int x : all) onpath[x] = true;
		if (all.size() == 1) return;
		int mid = all.size() / 2;
		vector<int> l(begin(all), begin(all) + mid), r(begin(all) + mid, end(all));
		kick(l), kick(r);
	};
	kick(allon);

//	for (int i = 0;i < n;++i) if (i != a && i != b) {
//		onpath[i] = false;
//		if (!qry_tf(a, b, onpath)) onpath[i] = true;
//	}

	vector<int> path;
	for (int i = 0;i < n;++i) if (i != a && i != b && onpath[i])
		path.pb(i);

	function<void(int, int)> qst = [&](int l, int r) {
		if (r-l+1 <= 1) return;
		int p = mrand(l, r);
		vector<int> lhs, rhs;

		onpath[ path[p] ] = false;

		for (int i = l;i <= r;++i) if (i != p) {
			if (qry_tf(a, path[i], onpath))
				lhs.pb(path[i]);
			else
				rhs.pb(path[i]);
		}

		onpath[ path[p] ] = true;

		int np = lhs.size();

		lhs.pb(path[p]);
		lhs.insert(end(lhs), AI(rhs));
		for (int i = 0, j = l;i < lhs.size();++i) {
			path[j++] = lhs[i];
		}

		qst(l, l + np-1);
		qst(l+np+1, r);
	};

	qst(0, (int) path.size() - 1);

	path.insert(begin(path), a);
	path.insert(end(path), b);

	return path;
}

void add_edge(int a, int b) {
	edge[a].pb(b), edge[b].pb(a);
	ans(a, b);
}
void put_in(vector<int> path) {
	for (int i = 1;i < path.size();++i)
		add_edge(path[i-1], path[i]);
	for (int x : path) on_tree[x] = true;
}
vector<int> dfs_order(int x, int lst = -1) {
	static vector<int> stk;
	if (lst == -1) stk.clear();
	stk.pb(x);
	for (int u : edge[x]) if (u != lst) {
		dfs_order(u, x);
	}
	if (lst == -1) return stk;
	return {};
}
void solve_tree() {
	vector<int> abp = find_path(0, 1);
	put_in(abp);

	for (int i = 0;i < n;++i) if (!on_tree[i]) {
		vector<int> in = dfs_order(0);
		vector<int> out;
		for (int j = 0;j < n;++j) if (!on_tree[j])
			out.pb(j);

		int l = 0, r = (int) in.size() - 1, mid;
		while (l < r) {
			mid = l + r >> 1;
			vector<int> ok = out;
			ok.insert(end(ok), begin(in), begin(in) + mid + 1);
			if (qry_list(0, i, ok))
				r = mid;
			else l = mid+1;
		}
		int p = in[l];
		put_in(find_path(p, i));
	}

}
void Detect(int T, int N) {
	n = N;

	if (T == 1) {
		for (int i = 0;i < n;++i)
			for (int j = i+1;j < n;++j)
				if (qry_list(i, j, {i, j}))
					ans(i, j);
		return;
	}
//
//	if (T == 2) {
//		auto a = find_path(0, N-1);
//
//		for (int i = 1;i < N;++i)
//			ans(a[i-1], a[i]);
//		return;
//	}
//
	if (T <= 4) {
		solve_tree();
	}
}

Compilation message (stderr)

park.cpp: In lambda function:
park.cpp:103:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  103 |   for (int i = 0, j = l;i < lhs.size();++i) {
      |                         ~~^~~~~~~~~~~~
park.cpp: In function 'void put_in(std::vector<int>)':
park.cpp:124:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  124 |  for (int i = 1;i < path.size();++i)
      |                 ~~^~~~~~~~~~~~~
park.cpp: In function 'void solve_tree()':
park.cpp:150:12: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
  150 |    mid = l + r >> 1;
      |          ~~^~~
park.cpp: At global scope:
park.cpp:20:12: warning: 'Place' defined but not used [-Wunused-variable]
   20 | static int Place[1400];
      |            ^~~~~

• Subtask 1: 10 / 10
• Subtask 2: 10 / 10
• Subtask 3: 27 / 27
• Subtask 4: 30 / 30
• Subtask 5: 0 / 23