Submission #1317201

#	Time	Username	Problem	Language	Result	Execution time	Memory
1317201		PlayVoltz	Split the Attractions (IOI19_split)	C++20	40 / 100	63 ms	26132 KiB

split

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

#define pb push_back
#define mp make_pair
#define pii pair<int, int>
#define fi first
#define se second

int counter=0;
vector<bool> ban, visited;
vector<int> low, disc, sz, ans, par;
vector<pii> vect;
vector<vector<int> > graph, adj;

void dfs(int node, int p){
	par[node]=p;
	disc[node]=low[node]=counter++;
	for (auto num:graph[node])if (num!=p){
		if (disc[num]==-1)dfs(num, node), low[node]=min(low[node], low[num]), adj[node].pb(num), sz[node]+=sz[num];
		else low[node]=min(low[node], disc[num]);
	}
}

void label(int node, int p, int t){
	visited[node]=1;
	if (vect[t].fi)--vect[t].fi, ans[node]=vect[t].se;
	for (auto num:adj[node])if (!ban[num])label(num, node, t);
}

void label2(int node, int p, int t){
	visited[node]=1;
	if (!vect[t].fi||ans[node])return;
	--vect[t].fi;
	ans[node]=vect[t].se;
	for (auto num:graph[node])if (!ans[num])label2(num, node, t);
}

vector<int> find_split(int n, int a, int b, int c, vector<int> p, vector<int> q){
	vect.pb(mp(a, 1));
	vect.pb(mp(b, 2));
	vect.pb(mp(c, 3));
	sort(vect.begin(), vect.end());
	ans.resize(n, 0);
	sz.resize(n, 1);
	adj.resize(n);
	low.resize(n);
	disc.resize(n, -1);
	graph.resize(n);
	par.resize(n, -1);
	visited.resize(n, 0);
	ban.resize(n, 0);
	for (int i=0; i<p.size(); ++i){
		graph[p[i]].pb(q[i]);
		graph[q[i]].pb(p[i]);
	}
	dfs(0, -1);
	int mid=-1;
	for (int i=0; i<n; ++i){
		int mx=0;
		for (auto num:adj[i])mx=max(mx, sz[num]);
		if (mx<a&&sz[i]>=a)mid=i;
	}
	assert(mid!=-1);
	int cc=sz[mid];
	for (auto num:adj[mid])if (low[num]<disc[mid]&&cc-sz[num]>=vect[0].fi)cc-=sz[num], ban[num]=1;
	if (n-cc>=vect[1].fi)swap(vect[0], vect[1]);
	if (n-cc>=vect[0].fi){
		label(mid, par[mid], 1);
		ban.assign(n, 0);
		for (int i=0; i<n; ++i)if (!visited[i]){
			label2(i, -1, 0);
			break;
		}
		for (int i=0; i<n; ++i)if (!ans[i])ans[i]=vect[2].se;
		return ans;
	}
	vector<int> temp(n, 0);
	return temp;
}

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