Submission #519554

#	Time	Username	Problem	Language	Result	Execution time	Memory
519554		LucaIlie	Connecting Supertrees (IOI20_supertrees)	C++17	40 / 100	202 ms	22724 KiB

supertrees

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

#define MAX_N 1000

using namespace std;

struct dsu {
    int n;
    int sef[MAX_N];

    void init( int x ) {
        int i;

        n = x;
        for ( i = 0; i < n; i++ )
            sef[i] = i;
    }

    int find( int x ) {
        if ( sef[x] != x )
            sef[x] = find( sef[x] );
        return sef[x];
    }

    void unionn( int x, int y ) {
        x = find( x );
        y = find( y );
        sef[y] = x;
    }
};

int construct( vector <vector <int>> p ) {
    int n, x, y, i, j;
    dsu forest1, forest2;
    vector <int> f1[MAX_N], f2[MAX_N];

    n = p.size();
    vector <vector <int>> b( n );
    forest1.init( n );
    forest2.init( n );


    for ( x = 0; x < n; x++ ) {
        for ( y = 0; y < n; y++ ) {
            if ( p[x][y] >= 1 )
                forest1.unionn( x, y );
            if ( p[x][y] >= 2 )
                forest2.unionn( x, y );
        }
    }

    for ( x = 0; x < n; x++ ) {
        f1[forest1.find( x )].push_back( x );
        f2[forest2.find( x )].push_back( x );
    }

    for ( i = 0; i < n; i++ ) {
        for ( j = 0; j < n; j++ )
            b[i].push_back( 0 );
    }

    /// 1
    for ( x = 0; x < n; x++ ) {
        if ( f1[x].size() > 1 ) {
            for ( i = 0; i < f1[x].size(); i++ ) {
                for ( j = i + 1; j < f1[x].size(); j++ ) {
                    if ( p[f1[x][i]][f1[x][j]] == 0 )
                        return 0;
                }
            }
            for ( i = 0; i < f1[x].size() - 1; i++ ) {
                b[f1[x][i]][f1[x][i + 1]] = 1;
                b[f1[x][i + 1]][f1[x][i]] = 1;
            }
        }
    }

    /// 2
    for ( x = 0; x < n; x++ ) {
        if ( f2[x].size() > 1 ) {
            for ( i = 0; i < f2[x].size(); i++ ) {
                for ( j = i + 1; j < f2[x].size(); j++ ) {
                    if ( p[f2[x][i]][f2[x][j]] <= 1 )
                        return 0;
                }
            }
            if ( f2[x].size() <= 2 )
                return 0;
            b[f2[x][0]][f2[x][f2[x].size() - 1]] = 1;
            b[f2[x][f2[x].size() - 1]][f2[x][0]] = 1;
        }
    }

    build( b );

    return 1;
}

Compilation message (stderr)

supertrees.cpp: In function 'int construct(std::vector<std::vector<int> >)':
supertrees.cpp:67:28: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   67 |             for ( i = 0; i < f1[x].size(); i++ ) {
      |                          ~~^~~~~~~~~~~~~~
supertrees.cpp:68:36: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   68 |                 for ( j = i + 1; j < f1[x].size(); j++ ) {
      |                                  ~~^~~~~~~~~~~~~~
supertrees.cpp:73:28: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   73 |             for ( i = 0; i < f1[x].size() - 1; i++ ) {
      |                          ~~^~~~~~~~~~~~~~~~~~
supertrees.cpp:83:28: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   83 |             for ( i = 0; i < f2[x].size(); i++ ) {
      |                          ~~^~~~~~~~~~~~~~
supertrees.cpp:84:36: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   84 |                 for ( j = i + 1; j < f2[x].size(); j++ ) {
      |                                  ~~^~~~~~~~~~~~~~

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