Submission #1068213

#	Time	Username	Problem	Language	Result	Execution time	Memory
1068213		Gromp15	Split the Attractions (IOI19_split)	C++17	0 / 100	1 ms	348 KiB

split

#include <bits/stdc++.h>
#include "split.h"
#define ll long long
#define ar array
#define all(x) x.begin(), x.end()
#define sz(x) (int)x.size()
using namespace std;
template<typename T> bool ckmin(T &a, const T &b) { return a > b ? a = b, 1 : 0; }
template<typename T> bool ckmax(T &a, const T &b) { return a < b ? a = b, 1 : 0; }
 
using namespace std;
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
#define rint(l, r) uniform_int_distribution<int>(l, r)(rng)
 
vector<int> find_split(int n, int a, int b, int c, vector<int> p, vector<int> q) {
	vector<vector<int>> adj(n);
	int m = sz(p);
	for (int i = 0; i < m; i++) {
		adj[p[i]].push_back(q[i]);
		adj[q[i]].push_back(p[i]);
	}
	vector<int> tin(n), low(n), stk;
	vector<bool> ap(n);
	vector<vector<int>> comps;
	int timer = 0;
	auto dfs = [&](auto&& s, int v, int p) -> void {
		tin[v] = low[v] = ++timer;
		stk.emplace_back(v);
		for (int u : adj[v]) if (u != p) {
			if (!tin[u]) {
				s(s, u, v);
				ckmin(low[v], low[u]);
				if (low[u] >= tin[v]) {
					ap[v] = 1;
					comps.push_back({v});
					for (int x = -1; x != u; ) {
						x = stk.back();
						stk.pop_back();
						comps.back().push_back(x);
					}
				}
			}
			else ckmin(low[v], tin[u]);
		}
	};
	dfs(dfs, 0, -1);
	ar<int, 3> size{a, b, c}, ord{1, 2, 3};
	sort(all(ord), [&](int x, int y) { return size[x-1] < size[y-1]; });
	int c1 = ord[0], c2 = ord[1], A = size[ord[0]-1], B = size[ord[1]-1];
	for (const auto& comp : comps) if (sz(comp) >= A + B) {
		vector<bool> in(n);
		for (int x : comp) in[x] = 1;
		vector<int> ans(n, ord[2]), dist(n, 1e9);
		queue<int> q;
		dist[comp[0]] = 0;
		q.push(comp[0]);
		int got = 0;
		while (q.size()) {
			int v = q.front(); q.pop();
			ans[v] = c1;
			if (++got == A) break;
			for (int u : adj[v]) if (in[u] && ckmin(dist[u], dist[v] + 1)) {
				q.push(u);
			}
		}
		assert(got == A);
		for (int x : comp) if (ans[x] == ord[2]) ans[x] = c2;
		return ans;
	}
  	assert(0);
	return {};
}

• Subtask 1: 0 / 7
• Subtask 2: 0 / 11
• Subtask 3: 0 / 22
• Subtask 4: 0 / 24
• Subtask 5: 0 / 36