Submission #519550

#	Time	Username	Problem	Language	Result	Execution time	Memory
519550		LucaIlie	Connecting Supertrees (IOI20_supertrees)	C++17	21 / 100	226 ms	22236 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, a, 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() ) {
            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]] <= a )
                        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;
            }
        }
    }
 
    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:69:21: warning: 'a' may be used uninitialized in this function [-Wmaybe-uninitialized]
   69 |                     if ( p[f1[x][i]][f1[x][j]] <= a )
      |                     ^~

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