Submission #1019948

#	Time	Username	Problem	Language	Result	Execution time	Memory
1019948		Mardonbekhazratov	슈퍼트리 잇기 (IOI20_supertrees)	C++17	100 / 100	161 ms	24308 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]) 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++){
		if(!vis[i]){
			in[i]=comp.size();
			comp.push_back({});
			dfs(i);
		}
	}
	for(int i=0;i<n;i++){
		for(int j=0;j<n;j++){
			if(v[i][j]>0 && in[i]!=in[j] || (in[i]==in[j] && v[i][j]==0) || v[i][j]==3) return 0;
		}
	}
	vector<vector<int>>ans(n,vector<int>(n,0));
	for(auto g:comp){
		vis.assign(n,false);
		vector<int>cycle;
		for(int x:g){
			if(vis[x]) continue;
			vector<int>line;
			for(int j=0;j<n;j++){
				if(v[x][j]==1) line.push_back(j);
			}
			for(int y:line){
				for(int z:line){
					if(v[y][z]!=1) return 0;
				}
				vis[y]=true;
			}
			for(int i=1;i<line.size();i++) ans[line[i]][line[i-1]]=ans[line[i-1]][line[i]]=1;
			cycle.push_back(line[0]);
		}
		if(cycle.size()==2) return 0;
		if(cycle.size()>2){
			for(int i=1;i<cycle.size();i++) ans[cycle[i-1]][cycle[i]]=ans[cycle[i]][cycle[i-1]]=1;
			ans[cycle[0]][cycle.back()]=ans[cycle.back()][cycle[0]]=1;
		}
	}
	build(ans);
	return 1;
}

Compilation message (stderr)

supertrees.cpp: In function 'int construct(std::vector<std::vector<int> >)':
supertrees.cpp:38:17: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
   38 |    if(v[i][j]>0 && in[i]!=in[j] || (in[i]==in[j] && v[i][j]==0) || v[i][j]==3) return 0;
supertrees.cpp:57:17: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   57 |    for(int i=1;i<line.size();i++) ans[line[i]][line[i-1]]=ans[line[i-1]][line[i]]=1;
      |                ~^~~~~~~~~~~~
supertrees.cpp:62:17: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   62 |    for(int i=1;i<cycle.size();i++) ans[cycle[i-1]][cycle[i]]=ans[cycle[i]][cycle[i-1]]=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