Submission #1013115

#	Time	Username	Problem	Language	Result	Execution time	Memory
1013115		LucaIlie	Graph (BOI20_graph)	C++17	17 / 100	5 ms	12392 KiB

Graph

#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;
#define nmax 100001
vector <int> edges[nmax], price[nmax], arbore[nmax], pricearb[nmax], v;
int daddy[nmax], type[nmax], paritate[nmax], comp[nmax], muchii[nmax];
double modificat[nmax];
const int inf = 1e8;
int find_daddy( int a ) {
    int x;
    if( daddy[a] == a )
        return a;
    x = find_daddy(daddy[a]);
    daddy[a] = x;
    return x;
}

void marry_daddy( int a, int b ) {
    int x, y;
    x = find_daddy( a );
    y = find_daddy( b );
    daddy[x] = y;
}

void dfs( int vf, int parent ) {
    int i, fiu;
    v.push_back(type[vf] * paritate[vf]);
    comp[find_daddy(vf)]++;
    muchii[find_daddy(vf)] += edges[vf].size();
    //cout << vf << "\n";
    for( i = 0; i < arbore[vf].size(); i++ ) {
        fiu = arbore[vf][i];
        if( fiu == parent )
            continue;
        type[fiu] = pricearb[vf][i] - type[vf];
        paritate[fiu] = -paritate[vf];
        //cout << fiu << " " << type[fiu] << " " << pricearb[vf][i] << " " << type[vf] << "\n";
        dfs( fiu, vf );
    }
}

void afisare( int x ) {
    if( (x + inf) % 2 == 0 )
        cout << x / 2 << " ";
    else
        cout << (x - 1) / 2 << ".5 ";
}


int main() {
    int n, m, i, a, b, c, j;
    bool ok = true;
    cin >> n >> m;
    for( i = 1; i <= n; i++ )
        daddy[i] = i;
    for( i = 0; i < m; i++ ) {
        cin >> a >> b >> c;
        edges[a].push_back( b );
        edges[b].push_back( a );
        price[a].push_back( c );
        price[b].push_back( c );
        if( find_daddy(a) != find_daddy(b) ) {
            marry_daddy( a, b );
            arbore[a].push_back(b);
            arbore[b].push_back(a);
            pricearb[a].push_back(c);
            pricearb[b].push_back(c);
        }
    }

    for( i = 1; i <= n; i++ ) {
        if( find_daddy(i) == i ) {
            paritate[i] = 1;
            dfs( i, 0 );
            if( 2 * comp[i] == muchii[i] + 2 ) {
                //cout << ".";
                sort(v.begin(), v.end());
                //for( j = 0; j < v.size(); j++ )
                  //  cout << v[j] << " ";
                //cout << "\n";
                modificat[find_daddy(i)] = -v[(v.size())/ 2];
            }
            v.clear();
        }
    }

    //for( i = 1; i <= n; i++ )
    //    cout << type[i] << " ";

    for( i = 1; i <= n; i++ ) {
        for( j = 0; j < edges[i].size(); j++ ) {
            if( type[i] + type[edges[i][j]] + (paritate[i] + paritate[edges[i][j]]) * modificat[find_daddy(i)] != price[i][j] ) {
                if( modificat[find_daddy(i)] == 0 && paritate[i] == paritate[edges[i][j]] )
                    modificat[find_daddy(i)] = (((double)price[i][j] - type[i] - type[edges[i][j]]) / 2) * paritate[i];
                else ok = false;
            }
        }
    }

    for( i = 1; i <= n; i++ ) {
        if( find_daddy(i) == i && modificat[i] == 0 ) {
            paritate[i] = 1;
            dfs( i, 0 );
            //cout << ".";
            sort(v.begin(), v.end());
            //for( j = 0; j < v.size(); j++ )
            //  cout << v[j] << " ";
            //cout << "\n";
            modificat[find_daddy(i)] = -v[(v.size())/ 2];
            v.clear();
        }
    }
    //cout << "\n";
    //for( i = 1; i <= n; i++ )
    //    cout << type[i] + paritate[i] * modificat[find_daddy(i)] << " ";
    if( !ok ) {
        cout << "NO\n";
        return 0;
    }

    cout << "YES\n";
    for( i = 1; i <= n; i++ )
        cout << type[i] + paritate[i] * modificat[find_daddy(i)] << " ";
    return 0;
}

Compilation message (stderr)

Graph.cpp: In function 'void dfs(int, int)':
Graph.cpp:32:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   32 |     for( i = 0; i < arbore[vf].size(); i++ ) {
      |                 ~~^~~~~~~~~~~~~~~~~~~
Graph.cpp: In function 'int main()':
Graph.cpp:92:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   92 |         for( j = 0; j < edges[i].size(); j++ ) {
      |                     ~~^~~~~~~~~~~~~~~~~

• Subtask 1: 5 / 5
• Subtask 2: 12 / 12
• Subtask 3: 0 / 17
• Subtask 4: 0 / 24
• Subtask 5: 0 / 42