Cod sursa(job #1163773)

Utilizator AlexandruValeanuAlexandru Valeanu AlexandruValeanu Data 1 aprilie 2014 16:58:47
Problema Cuplaj maxim de cost minim Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 3.76 kb
#include <iostream>
#include <fstream>
#include <vector>
#include <queue>

using namespace std;

const int Nmax = 603;
const int inf = 1e9;

struct NODE
{
    int nod;
    int dist;

    NODE( const int a = 0, const int b = 0 ) : nod( a ), dist( b ) {}

    bool operator < ( const NODE X ) const
    {
        return dist > X.dist;
    }
};

vector <int> G[Nmax];
priority_queue <NODE> MinHeap;
int C[Nmax][Nmax];
int F[Nmax][Nmax];
int indice[Nmax][Nmax];
int Cost[Nmax][Nmax];
int dist[Nmax], tata[Nmax], in_q[Nmax], coada[Nmax];

int N, M, DIM, E;

void BellmanFord( int S, int D )
{
    for ( int i = 0; i <= DIM; ++i )
    {
        dist[i] = inf;
        in_q[i] = 0;
    }

    int st, dr;
    coada[st = dr = 1] = S;
    in_q[S] = 0;
    dist[S] = 0;

    while ( st <= dr )
    {
        int nod = coada[ st++ ];
        in_q[nod] = 0;

        for ( auto x: G[nod] )
        {
            if ( dist[x] > dist[nod] + Cost[nod][x] && C[nod][x] > F[nod][x] )
            {
                dist[x] = dist[nod] + Cost[nod][x];

                if ( !in_q[x] )
                {
                    in_q[x] = 1;
                    coada[ ++dr ] = x;
                }
            }
        }
    }
}

void init( int S, int D )
{
    for ( int i = 0; i <= DIM; ++i )
    {
        for ( auto x: G[i] )
        {
            if ( dist[i] != inf && dist[x] != inf )
            {
                Cost[i][x] += dist[i] - dist[x];
            }
        }
    }

    for ( int i = 0; i <= DIM; ++i )
    {
        dist[i] = inf;
        tata[i] = 0;
    }

    dist[S] = 0;
}

int Dijkstra( int S, int D )
{
    init( S, D );
    MinHeap.push( NODE( S, 0 ) );

    while ( MinHeap.size() )
    {
        int nod = MinHeap.top().nod;
        int ddd = MinHeap.top().dist;

        MinHeap.pop();

        if ( dist[nod] != ddd ) continue;

        for ( auto x: G[nod] )
        {
            if ( dist[x] > dist[nod] + Cost[nod][x] && C[nod][x] > F[nod][x] )
            {
                dist[x] = dist[nod] + Cost[nod][x];
                tata[x] = nod;
                MinHeap.push( NODE( x, dist[x] ) );
            }
        }
    }

    return ( dist[D] < inf );
}

void MinCostMaxFlow( int S, int D, ostream &g )
{
    int flow = 0, fmin, distD = dist[D], costFlow = 0;

    while ( Dijkstra( S, D ) )
    {
        fmin = inf;

        for ( int nod = D; nod != S; nod = tata[nod] )
                fmin = min( fmin, C[ tata[nod] ][nod] - F[ tata[nod] ][nod] );

        for ( int nod = D; nod != S; nod = tata[nod] )
        {
            F[ tata[nod] ][nod] += fmin;
            F[nod][ tata[nod] ] -= fmin;
        }

        flow += fmin;
        distD += dist[D];
        costFlow += distD * fmin;
    }

    g << flow << " " << costFlow << "\n";

    for ( int i = 1; i <= N; ++i )
            for ( int j = N + 1; j <= N + M; ++j )
                    if ( F[i][j] == 1 )
                            g << indice[i][j] << " ";
}

void add_edge( int x, int y, int cap, int cost, int ind )
{
    G[x].push_back( y );
    G[y].push_back( x );

    indice[x][y] = indice[y][x] = ind;

    C[x][y] = cap;
    Cost[x][y] = +cost;
    Cost[y][x] = -cost;
}

int main()
{
    ifstream f("cmcm.in");
    ofstream g("cmcm.out");

    f >> N >> M >> E;

    int S = 0, D = N + M + 1;

    for ( int i = 1, a, b, c; i <= E; ++i )
    {
        f >> a >> b >> c;

        add_edge( a, b + N, 1, c, i );
    }

    for ( int i = 1; i <= N; ++i )
            add_edge( S, i, 1, 0, 0 );

    for ( int i = N + 1; i <= N + M; ++i )
            add_edge( i, D, 1, 0, 0 );

    DIM = N + M + 1;

    BellmanFord( S, D );
    MinCostMaxFlow( S, D, g );

    return 0;
}