Submission #1059051

#	Time	Username	Problem	Language	Result	Execution time	Memory
1059051		Lalic	Connecting Supertrees (IOI20_supertrees)	C++17	100 / 100	124 ms	28244 KiB

supertrees

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

#define fi first
#define se second
#define pb push_back
#define all(x) x.begin(), x.end()
#define allr(x) x.rbegin(), x.rend()
#define mp make_pair

typedef long long ll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
typedef complex<double> cd;

const int MAXN = 1e3+10;

int pai[MAXN], peso[MAXN];

int find(int x){ return (pai[x]==x ? x : pai[x]=find(pai[x])); }
void join(int a, int b){
	a=find(a);
	b=find(b);
	
	if(a==b) return;
	
	if(peso[a]>peso[b]) swap(a, b);
	pai[a]=b;
	peso[b]=max(peso[a]+1, peso[b]);
}

int root[MAXN];
vector<int> pres[MAXN];

int findRoot(int x){ return (root[x]==x ? x : root[x]=find(root[x])); }
void joinRoot(int a, int b){
	a=findRoot(a); b=findRoot(b);
	if(a==b) return;
	
	if((int)pres[a].size()>(int)pres[b].size()) swap(a, b);
	
	root[a]=b;
	for(auto u : pres[a])
		pres[b].pb(u);
}

vector<int> adj[MAXN];
int dobra[MAXN];
vector<vector<int>> mark;

void dfs(int ver, int num, int ini){
	mark[ini][ver]=num;
	
	for(auto u : adj[ver]){
		if(mark[ini][u]) continue;
		if(dobra[ver] && dobra[u]) dfs(u, 2, ini);
		else dfs(u, num, ini);
	}
}

int construct(vector<vector<int>> p) {
	int n = (int)p.size();
	vector<vector<int>> ans(n, vector<int>(n, 0));
	
	for(int i=0;i<n;i++) pai[i]=i, peso[i]=0, root[i]=i, pres[i]={i};
	
	for(int i=0;i<n;i++){
		for(int j=i+1;j<n;j++){
			if(p[i][j]==1 && find(i)!=find(j)){
				join(i, j);
				ans[i][j]=ans[j][i]=1;
			}
		}
	}
	
	vector<vector<int>> proc(n);
	for(int i=0;i<n;i++){
		for(int j=i+1;j<n;j++){
			if(p[i][j]!=2) continue;
			int x=find(i), y=find(j);
			if(x==y) return 0;
			
			joinRoot(x, y);
		}
	}
	
	for(int i=0;i<n;i++){
		if((int)pres[i].size()<=1) continue;
		
		if((int)pres[i].size()==2) return 0;
		
		for(auto u : pres[i]) dobra[u]=1;
		
		for(int j=1;j<(int)pres[i].size();j++)
			ans[pres[i][j-1]][pres[i][j]]=ans[pres[i][j]][pres[i][j-1]]=1;
		ans[pres[i].back()][pres[i][0]]=ans[pres[i][0]][pres[i].back()]=1;
	}
	
	for(int i=0;i<n;i++)
		for(int j=i+1;j<n;j++)
			if(ans[i][j]) adj[i].pb(j), adj[j].pb(i);
	
	mark.assign(n, vector<int>(n, 0));
	for(int i=0;i<n;i++)
		dfs(i, 1, i);
	
	for(int i=0;i<n;i++){
		for(int j=i+1;j<n;j++){
			if(mark[i][j]!=p[i][j]){
				return 0;
			}
		}
	}
	
	build(ans);
	return 1;
}

• Subtask 1: 11 / 11
• Subtask 2: 10 / 10
• Subtask 3: 19 / 19
• Subtask 4: 35 / 35
• Subtask 5: 21 / 21
• Subtask 6: 4 / 4