Submission #1228363

#	Time	Username	Problem	Language	Result	Execution time	Memory
1228363		Ludissey	Connecting Supertrees (IOI20_supertrees)	C++20	40 / 100	119 ms	22220 KiB

supertrees

#include "supertrees.h"
#include <bits/stdc++.h>
 
using namespace std;
 
#define all(a) (a.begin(), a.end())
#define sz(a) (int)a.size()

int n;

int construct(std::vector<std::vector<int>> p) {
	n=sz(p);
	vector<vector<int>> groups;
	vector<int> id(n);
	for (int i = 0; i < n; i++)
	{
		int g=-1;
		for (int j = 0; j < i; j++)
		{
			if(p[i][j]>=1) {
				if(g>-1&&id[j]!=g) return 0;
				g=id[j]; 
			}
		}
		if(g==-1) { groups.push_back({i}); id[i]=sz(groups)-1; }
		else {
			id[i]=g;
			groups[g].push_back(i);
		}
	}
	for (int i = 0; i < n; i++)
	{
		for (int j = 0; j < n; j++)
		{
			if((bool)p[i][j]!=(bool)(id[i]==id[j])) return 0;
		}
	}
	vector<vector<int>> bridge(n,vector<int>(n));
	/*for (int i = 0; i < sz(groups); i++)
	{
		for (int j = 1; j < sz(groups[i]); j++)
		{
			bridge[groups[i][j-1]][groups[i][j]]=bridge[groups[i][j]][groups[i][j-1]]=1;
		}
	}*/

	for (int i = 0; i < sz(groups); i++)
	{
		if(sz(groups[i])==1) continue;
		set<int> al;
		for (int j = 0; j < sz(groups[i]); j++)
		{
			bool b=true;
			for (int k = 0; k < sz(groups[i]); k++)
			{
				if(j==k) continue;
				if(p[groups[i][j]][groups[i][k]]<=1) b=false;
			}
			if(b) al.insert(groups[i][j]);
		}
		for (int j = 0; j < sz(groups[i]); j++)
		{
			if(al.find(groups[i][j])!=al.end()) continue;
			for (int k = 0; k < sz(groups[i]); k++)
			{
				if(j==k) continue;
				//if(p[groups[i][j]][groups[i][k]]==2&&al.find(groups[i][k])==al.end()) return 0; 
			}
		}
		int prev=-1;
		for (int j = 0; j < sz(groups[i]); j++)
		{
			if(al.find(groups[i][j])!=al.end()) continue;
			if(prev!=-1) bridge[prev][groups[i][j]]=bridge[groups[i][j]][prev]=1;
			prev=groups[i][j];
		}
		if(sz(al)==1) return 0;
		if(sz(al)==2&&sz(groups[i])==2) return 0;
		if(sz(al)>0){
			if(prev==-1) bridge[*al.begin()][*al.rbegin()]=bridge[*al.rbegin()][*al.begin()]=1;
			else bridge[prev][*(al.rbegin())]=bridge[*(al.rbegin())][prev]=1;
		}
		for (auto u : al)
		{
			if(prev!=-1) bridge[prev][u]=bridge[u][prev]=1;
			prev=u;
		}
	}
	build(bridge);		
	return 1;
}

• Subtask 1: 11 / 11
• Subtask 2: 10 / 10
• Subtask 3: 19 / 19
• Subtask 4: 0 / 35
• Subtask 5: 0 / 21
• Subtask 6: 0 / 4