Submission #434593

#	Time	Username	Problem	Language	Result	Execution time	Memory
434593		pere_gil	Connecting Supertrees (IOI20_supertrees)	C++14	40 / 100	284 ms	22084 KiB

supertrees

#include "supertrees.h"
#include "bits/stdc++.h"
using namespace std;
 
int p[1005];
 
void init(int n){
	for(int i=0;i<n;i++) p[i]=i;
}
 
int find_set(int n){
	return (p[n]==n) ? n : p[n]=find_set(p[n]);
}
 
bool same_set(int a, int b){
	return find_set(a)==find_set(b);
}
 
void union_set(int a, int b){
	if(!same_set(a,b)) p[find_set(a)]=find_set(b);
}
 
void form_group(vector<int> &g, vector<vector<int> > &v, bool is_2){
	if(g.size()==1) return;
	if(!is_2){
		for(int i=1;i<g.size();i++)
			v[g[i]][g[i-1]]=v[g[i-1]][g[i]]=1;
		return;
	}
 
	for(int i=0;i<g.size();i++){
		int j=(i+1)%g.size();
		v[g[i]][g[j]]=v[g[j]][g[i]]=1;
	}
}
 
int construct(vector<vector<int> > v){
	int n=v.size();
	init(n);
	
	for(int i=0;i<n;i++)
		for(int j=0;j<n;j++)
			if(v[i][j]) union_set(i,j);
 
	vector<vector<int> > g(n);
	for(int i=0;i<n;i++)
		g[find_set(i)].push_back(i);
 
	for(int i=0;i<n;i++)
		for(int j=0;j<n;j++)
			if(same_set(i,j) && v[i][j]==0) return 0;
 
	bool is_2=false;
	for(int i=0;i<n;i++)
		for(int j=0;j<n;j++)
		    if(v[i][j]==2) is_2=true;
	
	for(int i=0;i<n;i++)
		if(g[i].size()==2 && is_2) return 0;
	
	vector<vector<int> > ans(n,vector<int> (n,0));
	for(int i=0;i<n;i++)
		form_group(g[i],ans,is_2);
	build(ans);
	
	return 1;
}

Compilation message (stderr)

supertrees.cpp: In function 'void form_group(std::vector<int>&, std::vector<std::vector<int> >&, bool)':
supertrees.cpp:26:16: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   26 |   for(int i=1;i<g.size();i++)
      |               ~^~~~~~~~~
supertrees.cpp:31:15: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   31 |  for(int i=0;i<g.size();i++){
      |              ~^~~~~~~~~

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