Submission #419958

#	Time	Username	Problem	Language	Result	Execution time	Memory
419958		ioi	Connecting Supertrees (IOI20_supertrees)	C++14	96 / 100	336 ms	27184 KiB

supertrees

#include "supertrees.h"
#include <vector>
#include<bits/stdc++.h>
using namespace std ;
const int N = 1002;
int dsu[N] , sz[N];

int get(int u){
    if(u == dsu[u])
        return u ;

    return dsu[u] = get(dsu[u]);



}

void connect(int u , int v){


    u = get(u) , v = get(v);
    if(u == v)return ;

    if(sz[u] > sz[v])swap(u , v);

    sz[v] += sz[u];

    dsu[u] = v ;



}

bool same(int u , int v){
    u = get(u) , v = get(v);

    return u == v ;

}
vector<int> v , adj[N];

int construct(vector<vector<int>> p) {
	int n = p.size();
	vector<vector<int>> answer (n , vector<int> (n , 0));
    for(int i = 0 ; i < n ; i ++)sz[i] = 1 , dsu[i] = i ;
    int cnt[n] = {} , cnt1[n] = {};

    for(int i = 0 ; i < n ; i ++){
        for(int j = 0 ; j < n ; j ++){
            if(p[i][j])connect(i , j);
            if(i == j)continue;

            cnt[i] += (p[i][j] == 2 );cnt1[i] += (p[i][j] == 1);
            if(p[i][j] == 1 )adj[i].push_back(j) ;// , adj[j].push_back(i);

        }
    }
    map<int, set<int> > mp ;


    for(int i = 0 ; i < n ; i ++){
        for(int j = 0 ; j < n ;j ++)
        {
           // if(p[i][j] == 0&& same(i , j) || (p[i][j] && sz[get(dsu[i])] == 2))return 0 ;
             if(p[i][j] && i != j)mp[dsu[i]].insert(i) , mp[dsu[i]].insert(j);

        }
    }

    int vis[n] = {};

    for(auto f : mp){


        for(auto it : f.second){

            for(auto it2 : f.second){

                if(p[it][it2] == 0)return 0 ;

            }

        }
       // cout << "FF\n";
        vector<int> cycle   ;
        map<int , int > inc ;

        for(auto ff : f.second){

            if(!vis[ff]){
                vis[ff] ++ ;
                cycle.push_back(ff);
                inc[ff] ++ ;

                for(auto it : adj[ff]){
                    vis[it] ++ ;
                }

            }
        }

            if(cycle.size() == 1){

                int last = cycle[0];
                vector<int> v ;
                v.push_back(cycle[0]);
                for(auto it : adj[cycle[0]]){
                  //  cout << "last " << last << " " << it << endl ;
                    answer[it][last] = answer[last][it] = 1 ;
                    last = it ;
                    v.push_back(it);


                }

                for(int i = 0 ; i < v.size() ; i ++){
                    for(int j = i + 1 ; j < v.size() ; j ++){
                        if(p[v[i]][v[j]] != 1)
                            return 0 ;

                    }
                }



            }
            else {
                if(cycle.size() < 3)return 0 ;

                int last = cycle[0];

                for(int i = 1 ; i < cycle.size() ; i ++){

                    int curr = cycle[i];

                    answer[last][curr] = answer[curr][last] = 1 ;

                    last = curr ;


                }

                answer[cycle[0]][last] = answer[last][cycle[0]] = 1 ;


                for(auto ff : cycle){
                    int last = ff ;
                    for(auto it : adj[ff]){

                        answer[it][last] = answer[last][it] = 1 ;

                        last = it ;


                        for(auto it2 : adj[it]){
                            if(inc.count(it2) && it2 != ff)return 0 ;
                        }


                    }


                }

            }







    }


    for(int i = 0 ; i < n ; i ++)answer[i][i] = 0 ;
	build(answer);
	return 1;
}

Compilation message (stderr)

supertrees.cpp: In function 'int construct(std::vector<std::vector<int> >)':
supertrees.cpp:116:35: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  116 |                 for(int i = 0 ; i < v.size() ; i ++){
      |                                 ~~^~~~~~~~~~
supertrees.cpp:117:43: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  117 |                     for(int j = i + 1 ; j < v.size() ; j ++){
      |                                         ~~^~~~~~~~~~
supertrees.cpp:132:35: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  132 |                 for(int i = 1 ; i < cycle.size() ; i ++){
      |                                 ~~^~~~~~~~~~~~~~

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