Submission #1018892

#	Time	Username	Problem	Language	Result	Execution time	Memory
1018892		Mardonbekhazratov	Connecting Supertrees (IOI20_supertrees)	C++17	11 / 100	112 ms	24036 KiB

supertrees

#include "supertrees.h"
#include <vector>

using namespace std;

int n;
bool ok;
vector<int>in;
vector<vector<int>>v,comp;
vector<bool>vis;

void dfs(int x){
	comp[in[x]].push_back(x);
	vis[x]=true;
	for(int i=x+1;i<n;i++){
		if(v[x][i]){
			if(vis[i] && in[i]!=in[x]){
				ok=false;
				return;
			}
			if(vis[i]) continue;
			in[i]=in[x];
			dfs(i);
		}
	}
}

int construct(vector<vector<int>> p) {
	swap(p,v);
	n=v.size();
	in.resize(n);
	vis.assign(n,false);
	for(int i=0;i<n;i++){
		for(int j=0;j<n;j++){
			if(v[i][j]!=v[j][i]) return 0;
		}
	}
	ok=true;
	for(int i=0;i<n;i++){
		if(!vis[i]){
			in[i]=comp.size();
			comp.push_back({});
			dfs(i);
		}
	}
	if(!ok) return 0;
	vector<vector<int>>ans(n,vector<int>(n,0));
	for(auto g:comp){
		for(int i=1;i<g.size();i++){
			ans[g[i]][g[i-1]]=ans[g[i-1]][g[i]]=1;
			for(int j=0;j<i;j++){
				if(v[i][j]==0) return 0;
			}
		}
	}
	build(ans);
	return 1;
}

Compilation message (stderr)

supertrees.cpp: In function 'int construct(std::vector<std::vector<int> >)':
supertrees.cpp:49:16: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   49 |   for(int i=1;i<g.size();i++){
      |               ~^~~~~~~~~

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