Submission #1240477

#	Time	Username	Problem	Language	Result	Execution time	Memory
1240477		trimkus	Keys (IOI21_keys)	C++20	0 / 100	0 ms	324 KiB

keys

#include "keys.h"
#include <bits/stdc++.h>
using namespace std;


struct DSU {
	vector<int> e;
	vector<unordered_set<int>> st;
	DSU(int n) {
		e = vector<int>(n, -1);
		st = vector<unordered_set<int>>(n);
	}
	int get(int x) {
		return e[x] < 0 ? x : e[x] = get(e[x]);
	}
	bool can_unite(int x, int r) {
		x = get(x);
		return st[x].count(r);
	}
	void unite(int x, int y) {
		x = get(x);
		y = get(y);
		if (x == y) return;
		if (e[x] > e[y]) swap(x, y);
		if (st[x].size() > st[y].size()) {
			swap(st[x], st[y]);
		}
		for (auto& u : st[y]) {
			st[x].insert(u);
		}
		e[x] += e[y];
		st[y].clear();
		e[y] = x;
	}
};


std::vector<int> find_reachable(std::vector<int> r, std::vector<int> u, std::vector<int> v, std::vector<int> c) {
	int N = r.size();
	int M = u.size();
	vector<vector<array<int, 3>>> adj(N);
	for (int i = 0; i < (int)u.size(); ++i) {
		adj[u[i]].push_back({v[i], c[i], i});
		adj[v[i]].push_back({u[i], c[i], i});
	}
	vector<int> cnt(N);
	for (int i = 0; i < N; ++i) {
		vector<int> seen(N), inq(M);
		vector<int> now{i};
		unordered_set<int> have;
		have.insert(r[i]);
		vector<array<int, 3>> toadd;
		while (true) {
			bool added = false;
			while (now.size() > 0) {
				int v = now.back();
				now.pop_back();
				for (auto& [u, c, idx] : adj[v]) {
					if (seen[u] || inq[idx]) continue;
					toadd.push_back({u, c, idx});
					inq[idx] = true;
					added = true;
				}
			}
			sort(begin(toadd), end(toadd), [&](array<int, 3> x, array<int, 3> y) {
				if (!have.count(x[1])) return true;
				if (!have.count(y[1])) return false;
				return true;
			});
			// for (auto& u : toadd) {
			// 	cout << have.count(u[1]) << " ";
			// }
			// cout << "\n";
			while (toadd.size() > 0) {
				int c = toadd.back()[1];
				int v = toadd.back()[0];
				if (seen[v]) {
					toadd.pop_back();
					continue;;
				}
				if (have.count(c)) {
					seen[v] = 1;
					now.push_back(v);
					have.insert(r[v]);
					toadd.pop_back();
				} else {
					break;
				}
			}
			if (!added) break;
		}
		for (int j = 0; j < N; ++j) {
			cnt[i] += seen[j];
		}
	}
	vector<int> res(N);
	int mn = *min_element(begin(cnt), end(cnt));
	for (int i = 0; i < N; ++i) {
		if (mn == cnt[i]) {
			res[i] = 1;
		}
	}
	return res;
}

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