Cod sursa(job #896548)

Utilizator anca1243Popescu Anca anca1243 Data 27 februarie 2013 16:05:28
Problema Ciclu hamiltonian de cost minim Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.35 kb
#include <iostream>
#include <fstream>
#include <vector>
using namespace std;
ifstream in("hamilton.in");
ofstream out("hamilton.out");
const int N=20,INF=999999999;
vector <int> a[N];
int d[(1<<N)][N],n,m,p,cost[N][N];
void citire()
{
    int x,y,c;
    in>>n>>m;
    for(int i=1;i<=m;i++)
    {
        in>>x>>y>>c;
        a[y].push_back(x);
        cost[x][y]=c;
    }
}
void init()
{
    for(int i=0;i<(1<<n);i++)
        for(int j=0;j<n;j++)
            d[i][j]=INF;
}
void afisare()
{
    for(int i=0;i<(1<<n);i++)
    {
        for(int j=0;j<n;j++)
            out<<d[i][j]<<' ';
        out<<'\n';
    }
}
int main()
{
    citire();
    init();
    d[1][0]=0;
    for(int i=1;i<(1<<n);i+=2)
        for(int j=0;j<n;j++)
            if(i&(1<<j))
                for(size_t k=0;k<a[j].size();k++)
                {
                    p=a[j][k];
                    if(i&(1<<p))
                        if(d[i^(1<<j)][p] + cost[p][j] < d[i][j])
                            d[i][j]=d[i^(1<<j)][p] + cost[p][j];
                }
    int minim=INF;
    for(size_t i=0;i<a[0].size();i++)
    {
        int j=a[0][i];
        if(d[(1<<n)-1][j] + cost[j][0] <minim)
            minim = d[(1<<n)-1][j] + cost[j][0];
    }
    if(minim != INF)
        out<<minim;
    else
        out<<"Nu exista solutie";
    return 0;
}