Submission #306453

#	Time	Username	Problem	Language	Result	Execution time	Memory
306453		giorgikob	Connecting Supertrees (IOI20_supertrees)	C++14	100 / 100	255 ms	22268 KiB

supertrees

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

#include<bits/stdc++.h>
#define ll long long
#define ff first
#define ss second
#define pb push_back
using namespace std;


const int N = 1e3+5;
vector<int>c[N];
int cnt = 0, n;
int fix[N];
vector<int>chain;

void dfs(int x,vector<vector<int>>&p){
    fix[x] = 1;
    //cout << x << endl;
    c[cnt].pb(x);
    for(int i = 0; i < n; i++){
        if(fix[i]) continue;
        if(p[x][i]){
            dfs(i,p);
        }
    }
}


void dfs1(int x,vector<vector<int>>&p){
    fix[x] = 1;
    //c[cnt].pb(x);
    chain.pb(x);
    //cout << x << endl;
    for(int i = 0; i < n; i++){
        //cout << fix[i] << " ";
        if(fix[i]) continue;
        if(p[x][i] == 1){
            dfs1(i,p);
        }
    }
    //cout << endl;
}

bool check(vector<int>&v, vector<vector<int>>&p){

    for(int i = 0; i < (int)v.size(); i++){
        for(int j = 0; j < (int)v.size(); j++){
            if(p[v[i]][v[j]] == 2){
                return 0;
            }
        }
    }
    return 1;
}

void cr(int x,int y,vector<vector<int>>&v){
    v[x][y] = 1;
    v[y][x] = 1;
}

int construct(std::vector<std::vector<int>> p) {
    n = p.size();
    for(int i = 0; i < n; i++){
        for(int j = 0; j < n; j++){
            if(p[i][j] == 3){
                return 0;
            }
        }
    }
    for(int i = 0; i < n; i++){
        if(fix[i]) continue;
        cnt++;//cout << i << endl;
        dfs(i,p);
    }

    for(int i = 0; i < n; i++) fix[i] = 0;

    for(int i = 1; i <= cnt; i++){
        for(int j = 0; j < c[i].size(); j++){
            for(int t = 0; t < c[i].size(); t++){
                if(p[c[i][j]][c[i][t]] == 0){
                    return 0;
                }
            }
        }
    }

    vector<vector<int>>answer(n,vector<int>(n,0));
    vector<int>cyc;
    for(int i = 1; i <= cnt; i++){
        for(int j = 0; j < c[i].size(); j++){
            int x = c[i][j];
            if(fix[x]) continue;
            chain.clear();
            dfs1(x,p);
            if(check(chain,p) == 0){
                return 0;
            }
            for(int t = 0; t+1 < chain.size(); t++){
                int x = chain[t];
                int y = chain[t+1];
                cr(x,y,answer);
            }
            cyc.pb(chain[0]);
        }
        if(cyc.size() == 2) return 0;
        if(cyc.size() > 1)
        for(int i = 0; i < cyc.size(); i++){
            int x = cyc[i];
            int y = cyc[(i+1)%(int)cyc.size()];
            cr(x,y,answer);
        }

        cyc.clear();
    }

    build(answer);
    return 1;
}

Compilation message (stderr)

supertrees.cpp: In function 'int construct(std::vector<std::vector<int> >)':
supertrees.cpp:81:26: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   81 |         for(int j = 0; j < c[i].size(); j++){
      |                        ~~^~~~~~~~~~~~~
supertrees.cpp:82:30: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   82 |             for(int t = 0; t < c[i].size(); t++){
      |                            ~~^~~~~~~~~~~~~
supertrees.cpp:93:26: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   93 |         for(int j = 0; j < c[i].size(); j++){
      |                        ~~^~~~~~~~~~~~~
supertrees.cpp:101:32: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  101 |             for(int t = 0; t+1 < chain.size(); t++){
      |                            ~~~~^~~~~~~~~~~~~~
supertrees.cpp:110:26: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  110 |         for(int i = 0; i < cyc.size(); i++){
      |                        ~~^~~~~~~~~~~~

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