Submission #189321

#	Time	Username	Problem	Language	Result	Execution time	Memory
189321		kig9981	Split the Attractions (IOI19_split)	C++17	0 / 100	183 ms	19576 KiB

split

#include "split.h"
#include <bits/stdc++.h>

using namespace std;

vector<int> adj[100000], tree[100000], ans;
int node_cnt, num[100000], low[100000], cnt[100000], parent[100000], G[100000];

void dfs(int c)
{
	num[c]=low[c]=++node_cnt;
	cnt[c]=1;
	for(auto n: adj[c]) {
		if(num[n]==0) {
			parent[n]=c;
			tree[n].push_back(c);
			tree[c].push_back(n);
			dfs(n);
			low[c]=min(low[c],low[n]);
			cnt[c]+=cnt[n];
		}
		else if(c!=parent[n]) low[c]=min(low[c],num[n]);
	}
}

int centroid(int c)
{
	for(auto n: tree[c]) if(parent[n]==c && 2*cnt[n]>cnt[0]) return centroid(n);
	return c;
}

vector<int> find_split(int n, int a, int b, int c, vector<int> p, vector<int> q)
{
	vector<pair<int,int>> V;
	queue<int> Q;
	int tot=0; ans.clear();
	for(int i=node_cnt=0;i<n;i++) {
		num[i]=0;
		G[i]=-1;
		adj[i].clear();
		tree[i].clear();
	}
	V.emplace_back(a,1);
	V.emplace_back(b,2);
	V.emplace_back(c,3);
	sort(V.begin(),V.end());
	for(int i=0;i<p.size();i++) {
		adj[p[i]].push_back(q[i]);
		adj[q[i]].push_back(p[i]);
	}
	dfs(0);
	c=centroid(0);
	ans.resize(n);
	for(auto n: tree[c]) {
		if(parent[n]==c && cnt[n]>=V[1].first || parent[c]==n && cnt[0]-cnt[c]>=V[1].first) {
			ans[n]=V[1].second;
			ans[c]=V[0].second;
			Q.push(n);
			V[1].first--;
			V[0].first--;
			while(!Q.empty() && V[1].first) {
				int c=Q.front();
				Q.pop();
				for(auto n: tree[c]) if(ans[n]==0 && V[1].first) {
					ans[n]=ans[c];
					V[1].first--;
					Q.push(n);
				}
			}
			Q.push(c);
			while(!Q.empty() && V[0].first) {
				int c=Q.front();
				Q.pop();
				for(auto n: adj[c]) if(ans[n]==0 && V[0].first) {
					ans[n]=ans[c];
					V[0].first--;
					Q.push(n);
				}
			}
			for(auto &v: ans) if(v==0) v=V[2].second;
			assert(V[0].first==0 && V[1].first==0);
			return ans;
		}
		else if(parent[n]==c && cnt[n]>=V[0].first || parent[c]==n && cnt[0]-cnt[c]>=V[0].first) {
			ans[n]=V[0].second;
			ans[c]=V[1].second;
			V[1].first--;
			V[0].first--;
			Q.push(n);
			while(!Q.empty() && V[0].first) {
				int c=Q.front();
				Q.pop();
				for(auto n: tree[c]) if(ans[n]==0 && V[0].first) {
					ans[n]=ans[c];
					V[0].first--;
					Q.push(n);
				}
			}
			Q.push(c);
			while(!Q.empty() && V[1].first) {
				int c=Q.front();
				Q.pop();
				for(auto n: adj[c]) if(ans[n]==0 && V[1].first) {
					ans[n]=ans[c];
					V[1].first--;
					Q.push(n);
				}
			}
			for(auto &v: ans) if(v==0) v=V[2].second;
			assert(V[0].first==0 && V[1].first==0);
			return ans;
		}
	}
	G[c]=0;
	G[parent[c]]=1;
	Q.push(parent[c]);
	while(!Q.empty()) {
		int c=Q.front();
		Q.pop();
		for(auto n: tree[c]) if(G[n]==-1) {
			G[n]=G[c];
			Q.push(n);
		}
	}
	tot=n-cnt[c];
	for(auto n: tree[c]) if(parent[n]==c && low[n]<num[c]) {
		G[n]=1;
		Q.push(n);
		while(!Q.empty()) {
			int c=Q.front();
			Q.pop();
			for(auto n: tree[c]) if(G[n]==-1) {
				G[n]=G[c];
				Q.push(n);
			}
		}
		if((tot+=cnt[n])>=V[0].first) {
			ans[parent[c]]=V[0].second;
			ans[c]=V[1].second;
			V[1].first--;
			V[0].first--;
			Q.push(parent[c]);
			while(!Q.empty() && V[0].first) {
				int c=Q.front();
				Q.pop();
				for(auto n: adj[c]) if(G[n]==G[c] && ans[n]==0 && V[0].first) {
					ans[n]=ans[c];
					V[0].first--;
					Q.push(n);
				}
			}
			Q.push(c);
			while(!Q.empty() && V[1].first) {
				int c=Q.front();
				Q.pop();
				for(auto n: adj[c]) if(ans[n]==0 && V[1].first) {
					ans[n]=ans[c];
					V[1].first--;
					Q.push(n);
				}
			}
			for(auto &v: ans) if(v==0) v=V[2].second;
			return ans;
		}
	}
	return ans;
}

Compilation message (stderr)

split.cpp: In function 'std::vector<int> find_split(int, int, int, int, std::vector<int>, std::vector<int>)':
split.cpp:47:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i=0;i<p.size();i++) {
              ~^~~~~~~~~
split.cpp:55:19: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
   if(parent[n]==c && cnt[n]>=V[1].first || parent[c]==n && cnt[0]-cnt[c]>=V[1].first) {
      ~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~
split.cpp:84:24: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
   else if(parent[n]==c && cnt[n]>=V[0].first || parent[c]==n && cnt[0]-cnt[c]>=V[0].first) {
           ~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~

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