void Prim2opt::TravelingSalesman(Grafo<Ciudad> &g, unsigned int r) {
unsigned int visited[g.getSize()];
for (unsigned int i = 0; i <= g.getSize(); i++)
visited[i] = 0;
Grafo<unsigned int> T = getPrim(g, 0);
list<unsigned int> L;
preorderTreeWalk(T, r, visited, L);
//L.push_back(r); Eso por si se quiere hacer realmente hamiltoniano.
localSearch(g, L);
printList(L);
cout <<" - ";
cout << getTourCost(g, L) << endl;
}
void Prim2opt::localSearch(Grafo<Ciudad> &g, list<unsigned int> &L) {
list<unsigned int> auxList = L;
unsigned int initialCost = getTourCost(g, L);
unsigned int random1, random2;
unsigned int maxx, minx;
for(unsigned int i = 0; i < g.getSize()*200; i++) {
random1 = rand() % auxList.size();
if(random1 <= 0) random1++;
if(random1 > (auxList.size()-2)) random1--;
random2 = rand() % auxList.size();
if(random2 <= 0) random2++;
if(random2 > (auxList.size()-2)) random2--;
list<unsigned int>::iterator it = auxList.begin();
list<unsigned int>::iterator it2 = auxList.begin();
maxx = max(random1, random2);
minx = min(random1, random2);
advance(it, minx);
advance(it2, maxx);
list<unsigned int> rev (it, it2);
rev.reverse();
list<unsigned int> temp (auxList.begin(), it);
temp.splice(temp.end(), rev);
temp.splice(temp.end(), auxList, it2, auxList.end());
auxList = temp;
if(getTourCost(g, auxList) < initialCost){
initialCost = getTourCost(g, auxList);
L = auxList;
} else {
auxList = L;
}
}
}
Grafo<unsigned int> Prim2opt::getPrim(Grafo<Ciudad> &g, unsigned int vertice) {
unsigned int N = g.getSize();
int root[N];
unsigned int distance[N];
unsigned int visited[N];
for (unsigned int i = 0; i < N; i++) {
distance[i] = INFINITE;
root[i] = -1;
visited[i] = 0;
}
priority_queue <ui_ui, vector<ui_ui>, greater<ui_ui> > pq;
distance[vertice] = 0;
pq.push(ui_ui(0, vertice));
while (!pq.empty()){
unsigned int aux = pq.top().second;
pq.pop();
if (visited[aux] == 1)
continue;
visited[aux] = 1;
list<unsigned int> adj;
g.getAdjacents(aux, adj);
list<unsigned int>::iterator it = adj.begin();
while (it != adj.end()){
unsigned int dist = g.getData(aux, *it).getCost();
if (dist < distance[*it] && !visited[*it]){
distance[*it] = dist;
root[*it] = aux;
pq.push(ui_ui(dist,*it));
}
it++;
}
}
Grafo<unsigned int> mst = getMinimumSpanningTree(root, distance, N, vertice);
return mst;
}
