Submission #815150

#	Time	Username	Problem	Language	Result	Execution time	Memory
815150		gesgha	Keys (IOI21_keys)	C++17	67 / 100	3023 ms	55932 KiB

keys

#include <bits/stdc++.h>
 
#define fr(i, a, b) for(int i = a; i <= b; i++)
#define rf(i, a, b) for(int i = a; i >= b; i--)
#define fe(x, y) for (auto& x : y)
 
#define fi first
#define se second
#define pb push_back
 
#define all(x) x.begin(), x.end()
#define pw(x) (1LL << (x))
#define sz(x) (int)x.size()
 
using namespace std;
 
#include <ext/pb_ds/assoc_container.hpp>
using namespace __gnu_pbds;
#define fbo find_by_order
#define ook order_of_key
template <typename T>
using oset = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
 
template <typename T>
using ve = vector <T>;
 
template <typename T>
bool umx (T& a, T b) { return a < b ? a = b, 1 : 0; }
 
template <typename T>
bool umn (T& a, T b) { return a > b ? a = b, 1 : 0; }
 
using ll = long long;
using ld = long double;
using pll = pair <ll, ll>;
using pii = pair <int, int>;
using ull = unsigned long long;
 
const int oo = 1e9;
const ll OO = 1e18;
const int N = 3e5 + 10;
const int M = 5e3 + 100;
const int mod = 1e9 + 7;
const bool TEST = 0;

int n;
ve <pii> G[N];
ve <pii> NG[N];
int root[N];
int get(int u) {
	return u == root[u] ? u : root[u] = get(root[u]);
}

void uni(int u, int v) {
	u = get(u);
	v = get(v);
	root[u] = v;
}

int col[N];
int A = 1e9;
ve <int> Ans;
int WAS[N], global;
int bad[N];

void bfs(int st) {
	WAS[st] = global;
	set <pii> E;
	ve <bool> vis(n, 0), have(n, 0);
	ve <int> id;
	queue <int> q;
	q.push(st);
	while (sz(q)) {
		int u = q.front();
		q.pop();
		if (get(u) != st) {
			uni(st, u);
			WAS[st] = global;
			return;
		}
		id.pb(u);
		have[col[u]] = 1;
		for (auto [to, clr] : G[u]) if (!vis[to]) {
			if (have[clr]) {
				vis[to] = 1;
				q.push(to);
			} else {
				E.insert({clr, to});
			}
		}
		while (1) {
			auto it = E.lower_bound(make_pair(col[u], -1));
			if (it != E.end() && (*it).fi == col[u]) {
				if (!vis[(*it).se]) {
					vis[(*it).se] = 1;
					q.push((*it).se);
				}
				E.erase(it);
			} else {
				break;
			}
		}
	}
	bad[st] = 1;
	if (sz(id) < A) {
		A = sz(id);
		Ans.clear();
	}
	if (A == sz(id)) fe(x, id) Ans.pb(x);
}

vector<int> find_reachable(vector <int> r, vector <int> u, vector <int> v, vector <int> c) {
	n = sz(r);
	for (int i = 0; i < n; i++) root[i] = i;
	vector<int> ans(n, 0);
	ve <int> C(n, 0);
	for (int i = 0; i < n; i++) col[i] = r[i];
	for (int i = 0; i < sz(u); i++) {
		G[u[i]].pb({v[i], c[i]});
		G[v[i]].pb({u[i], c[i]});
	}
	for (global = 1;; global++) {
		bool c = 0;
		for (int i = 0; i < n; i++) {
			if (i == get(i) && !bad[i]) {
				if (WAS[i] != global) {
					bfs(i);
					c = 1;
				}
			}
		}
		if (!c) break;
	}
	fe(x, Ans) ans[x] = 1;
	return ans;
}

• Subtask 1: 9 / 9
• Subtask 2: 11 / 11
• Subtask 3: 17 / 17
• Subtask 4: 30 / 30
• Subtask 5: 0 / 33