generate-shapes/src/util/graph/EDijkstra.tpp
2022-03-28 14:59:55 +02:00

564 lines
18 KiB
C++

// Copyright 2017, University of Freiburg,
// Chair of Algorithms and Data Structures.
// Authors: Patrick Brosi <brosi@informatik.uni-freiburg.de>
// _____________________________________________________________________________
template <typename N, typename E, typename C>
C EDijkstra::shortestPathImpl(Node<N, E>* from, const std::set<Node<N, E>*>& to,
const util::graph::CostFunc<N, E, C>& costFunc,
const util::graph::HeurFunc<N, E, C>& heurFunc,
EList<N, E>* resEdges, NList<N, E>* resNodes) {
std::set<Edge<N, E>*> frEs;
std::set<Edge<N, E>*> toEs;
frEs.insert(from->getAdjListOut().begin(), from->getAdjListOut().end());
for (auto n : to) {
toEs.insert(n->getAdjListIn().begin(), n->getAdjListIn().end());
}
C cost = shortestPathImpl(frEs, toEs, costFunc, heurFunc, resEdges, resNodes);
// the beginning node is not included in our edge based dijkstra
if (resNodes) resNodes->push_back(from);
return cost;
}
// _____________________________________________________________________________
template <typename N, typename E, typename C>
C EDijkstra::shortestPathImpl(Edge<N, E>* from, const std::set<Node<N, E>*>& to,
const util::graph::CostFunc<N, E, C>& costFunc,
const util::graph::HeurFunc<N, E, C>& heurFunc,
EList<N, E>* resEdges, NList<N, E>* resNodes) {
std::set<Edge<N, E>*> frEs;
std::set<Edge<N, E>*> toEs;
frEs.insert(from);
for (auto n : to) {
toEs.insert(n->getAdjListIn().begin(), n->getAdjListIn().end());
}
C cost = shortestPathImpl(frEs, toEs, costFunc, heurFunc, resEdges, resNodes);
return cost;
}
// _____________________________________________________________________________
template <typename N, typename E, typename C>
C EDijkstra::shortestPathImpl(const std::set<Node<N, E>*>& from,
const std::set<Node<N, E>*>& to,
const util::graph::CostFunc<N, E, C>& costFunc,
const util::graph::HeurFunc<N, E, C>& heurFunc,
EList<N, E>* resEdges, NList<N, E>* resNodes) {
std::set<Edge<N, E>*> frEs;
std::set<Edge<N, E>*> toEs;
for (auto n : from) {
frEs.insert(n->getAdjListIn().begin(), n->getAdjListIn().end());
}
for (auto n : to) {
toEs.insert(n->getAdjListIn().begin(), n->getAdjListIn().end());
}
C cost = shortestPathImpl(frEs, toEs, costFunc, heurFunc, resEdges, resNodes);
return cost;
}
// _____________________________________________________________________________
template <typename N, typename E, typename C>
C EDijkstra::shortestPathImpl(const std::set<Edge<N, E>*>& from,
const std::set<Edge<N, E>*>& to,
const util::graph::CostFunc<N, E, C>& costFunc,
const util::graph::HeurFunc<N, E, C>& heurFunc,
EList<N, E>* resEdges, NList<N, E>* resNodes) {
if (from.size() == 0 || to.size() == 0) return costFunc.inf();
Settled<N, E, C> settled;
PQ<N, E, C> pq;
bool found = false;
// at the beginning, put all edges on the priority queue,
// init them with their own cost
for (auto e : from) {
C c = costFunc(0, 0, e);
C h = heurFunc(e, to);
pq.push(c + h, {e, (Edge<N, E>*)0, (Node<N, E>*)0, c});
}
RouteEdge<N, E, C> cur;
while (!pq.empty()) {
if (costFunc.inf() <= pq.topKey()) return costFunc.inf();
auto se = settled.find(pq.topVal().e);
if (se != settled.end()) {
// to allow non-consistent heuristics
if (se->second.d <= pq.topVal().d) {
pq.pop();
continue;
}
}
EDijkstra::ITERS++;
cur = pq.topVal();
pq.pop();
settled[cur.e] = cur;
if (to.find(cur.e) != to.end()) {
found = true;
break;
}
relax(cur, to, costFunc, heurFunc, pq);
}
if (!found) return costFunc.inf();
buildPath(cur.e, settled, resNodes, resEdges);
return cur.d;
}
// _____________________________________________________________________________
template <typename N, typename E, typename C>
std::unordered_map<Edge<N, E>*, C> EDijkstra::shortestPathImpl(
const std::set<Edge<N, E>*>& from,
const util::graph::CostFunc<N, E, C>& costFunc, bool rev) {
std::unordered_map<Edge<N, E>*, C> costs;
Settled<N, E, C> settled;
PQ<N, E, C> pq;
std::set<Edge<N, E>*> to;
for (auto e : from) {
pq.push(C(), {e, (Edge<N, E>*)0, (Node<N, E>*)0, costFunc(0, 0, e)});
}
RouteEdge<N, E, C> cur;
while (!pq.empty()) {
auto se = settled.find(pq.topVal().e);
if (se != settled.end()) {
// to allow non-consistent heuristics
if (se->second.d <= pq.topVal().d) {
pq.pop();
continue;
}
}
EDijkstra::ITERS++;
cur = pq.topVal();
pq.pop();
settled[cur.e] = cur;
costs[cur.e] = cur.d;
buildPath(cur.e, settled, (NList<N, E>*)0, (EList<N, E>*)0);
if (rev)
relaxInv(cur, costFunc, pq);
else
relax(cur, to, costFunc, ZeroHeurFunc<N, E, C>(), pq);
}
return costs;
}
// _____________________________________________________________________________
template <typename N, typename E, typename C>
std::unordered_map<Edge<N, E>*, C> EDijkstra::shortestPathImpl(
Edge<N, E>* from, const std::set<Edge<N, E>*>& to,
const util::graph::CostFunc<N, E, C>& costFunc,
const util::graph::HeurFunc<N, E, C>& heurFunc,
std::unordered_map<Edge<N, E>*, EList<N, E>*> resEdges,
std::unordered_map<Edge<N, E>*, NList<N, E>*> resNodes) {
std::unordered_map<Edge<N, E>*, C> costs;
if (to.size() == 0) return costs;
// init costs with inf
for (auto e : to) costs[e] = costFunc.inf();
Settled<N, E, C> settled;
PQ<N, E, C> pq;
size_t found = 0;
C c = costFunc(0, 0, from);
C h = heurFunc(from, to);
pq.push(c + h, {from, (Edge<N, E>*)0, (Node<N, E>*)0, c});
RouteEdge<N, E, C> cur;
while (!pq.empty()) {
if (costFunc.inf() <= pq.topKey()) return costs;
auto se = settled.find(pq.topVal().e);
if (se != settled.end()) {
// to allow non-consistent heuristics
if (se->second.d <= pq.topVal().d) {
pq.pop();
continue;
}
}
EDijkstra::ITERS++;
cur = pq.topVal();
pq.pop();
settled[cur.e] = cur;
if (to.find(cur.e) != to.end()) {
found++;
costs[cur.e] = cur.d;
buildPath(cur.e, settled, resNodes[cur.e], resEdges[cur.e]);
}
if (found == to.size()) return costs;
relax(cur, to, costFunc, heurFunc, pq);
}
return costs;
}
// _____________________________________________________________________________
template <typename N, typename E, typename C>
std::unordered_map<Edge<N, E>*, C> EDijkstra::shortestPathImpl(
const std::set<Edge<N, E>*>& from, const std::set<Edge<N, E>*>& to,
const std::unordered_map<Edge<N, E>*, C>& initCosts, C stall,
const util::graph::CostFunc<N, E, C>& costFunc,
const util::graph::HeurFunc<N, E, C>& heurFunc,
std::unordered_map<Edge<N, E>*, EList<N, E>*> resEdges,
std::unordered_map<Edge<N, E>*, NList<N, E>*> resNodes) {
/**
* Shortest paths from the set <from> to ALL nodes in <TO>, but
* init <from> nodes with costs (this is equivalent to adding an auxiliary
* node S, connecting it with directed edges to all <from>, setting the
* costs of these edges to the initial costs and run a 1->N Dijkstra from S
**/
std::unordered_map<Edge<N, E>*, C> costs;
if (to.size() == 0) return costs;
// init costs with inf
for (auto e : to) costs[e] = costFunc.inf();
SettledInit<N, E, C> settled;
PQInit<N, E, C> pq;
size_t found = 0;
// put all nodes in from onto the PQ with their initial costs, also set
// the initial cost as a heuristic starting point!
for (auto e : from) {
C iCost = initCosts.find(e)->second;
assert(iCost + heurFunc(e, to) >= iCost);
pq.push(iCost + heurFunc(e, to),
{e, (Edge<N, E>*)0, (Node<N, E>*)0, iCost});
}
RouteEdgeInit<N, E, C> cur;
while (!pq.empty()) {
if (costFunc.inf() <= pq.topKey()) return costs;
if (stall <= pq.topVal().dwi) return costs;
auto se = settled.find(pq.topVal().e);
if (se != settled.end()) {
// to allow non-consistent heuristics
if (se->second.d <= pq.topVal().d) {
pq.pop();
continue;
}
}
EDijkstra::ITERS++;
cur = pq.topVal();
pq.pop();
settled[cur.e] = cur;
if (to.find(cur.e) != to.end()) {
found++;
costs[cur.e] = cur.d;
buildPathInit(cur.e, settled, resNodes[cur.e], resEdges[cur.e]);
if (found == to.size()) return costs;
}
relaxInit(cur, to, stall, costFunc, heurFunc, pq);
}
return costs;
}
// _____________________________________________________________________________
template <typename N, typename E, typename C>
std::unordered_map<Edge<N, E>*, std::pair<Edge<N, E>*, C>>
EDijkstra::shortestPathImpl(const std::set<Edge<N, E>*>& from,
const std::set<Edge<N, E>*>& to,
const std::unordered_map<Edge<N, E>*, C>& initCosts,
C stall,
const util::graph::CostFunc<N, E, C>& costFunc,
const util::graph::HeurFunc<N, E, C>& heurFunc) {
/**
* Shortest paths from the set <from> to ALL nodes in <TO>, but
* init <from> nodes with costs (this is equivalent to adding an auxiliary
* node S, connecting it with directed edges to all <from>, setting the
* costs of these edges to the initial costs and run a 1->N Dijkstra from S
**/
std::unordered_map<Edge<N, E>*, std::pair<Edge<N, E>*, C>> costs;
if (to.size() == 0) return costs;
// init costs with inf
for (auto e : to) costs[e] = {0, costFunc.inf()};
SettledInitNoRes<N, E, C> settled;
PQInitNoRes<N, E, C> pq;
size_t found = 0;
// put all nodes in from onto the PQ with their initial costs, also set
// the initial cost as a heuristic starting point!
// set the parent to the edge itself - in this version, the parent is ALWAYS
// the start edge, as we don't need the exact paths later on
for (auto e : from) {
C iCost = initCosts.find(e)->second;
assert(iCost + heurFunc(e, to) >= iCost);
pq.push(iCost + heurFunc(e, to), {e, e, iCost});
}
RouteEdgeInitNoRes<N, E, C> cur;
while (!pq.empty()) {
if (costFunc.inf() <= pq.topKey()) return costs;
if (stall <= pq.topVal().dwi) return costs;
auto se = settled.find(pq.topVal().e);
if (se != settled.end()) {
// to allow non-consistent heuristics
if (se->second.d <= pq.topVal().d) {
pq.pop();
continue;
}
}
EDijkstra::ITERS++;
cur = pq.topVal();
pq.pop();
settled[cur.e] = cur;
if (to.find(cur.e) != to.end()) {
found++;
costs[cur.e] = {cur.parent, cur.d};
if (found == to.size()) return costs;
}
relaxInitNoResEdgs(cur, to, stall, costFunc, heurFunc, pq);
}
return costs;
}
// _____________________________________________________________________________
template <typename N, typename E, typename C>
void EDijkstra::relaxInv(RouteEdge<N, E, C>& cur,
const util::graph::CostFunc<N, E, C>& costFunc,
PQ<N, E, C>& pq) {
// handling undirected graph makes no sense here
for (const auto edge : cur.e->getFrom()->getAdjListIn()) {
if (edge == cur.e) continue;
C newC = costFunc(edge, cur.e->getFrom(), cur.e);
newC = cur.d + newC;
if (costFunc.inf() <= newC) continue;
if (newC < cur.d) continue; // cost overflow!
pq.push(C(), {edge, cur.e, cur.e->getFrom(), newC});
}
}
// _____________________________________________________________________________
template <typename N, typename E, typename C>
void EDijkstra::relaxInitNoResEdgs(
RouteEdgeInitNoRes<N, E, C>& cur, const std::set<Edge<N, E>*>& to, C stall,
const util::graph::CostFunc<N, E, C>& costFunc,
const util::graph::HeurFunc<N, E, C>& heurFunc, PQInitNoRes<N, E, C>& pq) {
if (cur.e->getFrom()->hasEdgeIn(cur.e) &&
cur.e->getFrom() != cur.e->getTo()) {
// for undirected graphs
for (const auto edge : cur.e->getFrom()->getAdjListOut()) {
if (edge == cur.e) continue;
C newC = costFunc(cur.e, cur.e->getFrom(), edge);
C newDwi = cur.dwi + newC;
if (stall <= newDwi) continue;
if (costFunc.inf() <= newC) continue;
newC = cur.d + newC;
if (newC < cur.d) continue; // cost overflow!
if (costFunc.inf() <= newC) continue;
const C& h = heurFunc(edge, to);
if (costFunc.inf() <= h) continue;
newC = cur.d + newC;
const C& newH = newC + h;
if (newH < newC) continue; // cost overflow!
pq.push(newH, {edge, cur.parent, newC, newDwi});
}
}
for (const auto edge : cur.e->getTo()->getAdjListOut()) {
if (edge == cur.e) continue;
C newC = costFunc(cur.e, cur.e->getTo(), edge);
C newDwi = cur.dwi + newC;
if (stall <= newDwi) continue;
if (costFunc.inf() <= newC) continue;
newC = cur.d + newC;
if (newC < cur.d) continue; // cost overflow!
if (costFunc.inf() <= newC) continue;
const C& h = heurFunc(edge, to);
if (costFunc.inf() <= h) continue;
const C& newH = newC + h;
if (newH < newC) continue; // cost overflow!
pq.push(newH, {edge, cur.parent, newC, newDwi});
}
}
// _____________________________________________________________________________
template <typename N, typename E, typename C>
void EDijkstra::relaxInit(RouteEdgeInit<N, E, C>& cur,
const std::set<Edge<N, E>*>& to, C stall,
const util::graph::CostFunc<N, E, C>& costFunc,
const util::graph::HeurFunc<N, E, C>& heurFunc,
PQInit<N, E, C>& pq) {
if (cur.e->getFrom()->hasEdgeIn(cur.e) &&
cur.e->getFrom() != cur.e->getTo()) {
// for undirected graphs
for (const auto edge : cur.e->getFrom()->getAdjListOut()) {
if (edge == cur.e) continue;
C newC = costFunc(cur.e, cur.e->getFrom(), edge);
C newDwi = cur.dwi + newC;
if (stall <= newDwi) continue;
if (costFunc.inf() <= newC) continue;
newC = cur.d + newC;
if (newC < cur.d) continue; // cost overflow!
if (costFunc.inf() <= newC) continue;
const C& h = heurFunc(edge, to);
if (costFunc.inf() <= h) continue;
newC = cur.d + newC;
const C& newH = newC + h;
if (newH < newC) continue; // cost overflow!
pq.push(newH, {edge, cur.e, cur.e->getFrom(), newC, newDwi});
}
}
for (const auto edge : cur.e->getTo()->getAdjListOut()) {
if (edge == cur.e) continue;
C newC = costFunc(cur.e, cur.e->getTo(), edge);
C newDwi = cur.dwi + newC;
if (stall <= newDwi) continue;
if (costFunc.inf() <= newC) continue;
newC = cur.d + newC;
if (newC < cur.d) continue; // cost overflow!
if (costFunc.inf() <= newC) continue;
const C& h = heurFunc(edge, to);
if (costFunc.inf() <= h) continue;
const C& newH = newC + h;
if (newH < newC) continue; // cost overflow!
pq.push(newH, {edge, cur.e, cur.e->getTo(), newC, newDwi});
}
}
// _____________________________________________________________________________
template <typename N, typename E, typename C>
void EDijkstra::relax(RouteEdge<N, E, C>& cur, const std::set<Edge<N, E>*>& to,
const util::graph::CostFunc<N, E, C>& costFunc,
const util::graph::HeurFunc<N, E, C>& heurFunc,
PQ<N, E, C>& pq) {
if (cur.e->getFrom()->hasEdgeIn(cur.e) &&
cur.e->getFrom() != cur.e->getTo()) {
// for undirected graphs
for (const auto edge : cur.e->getFrom()->getAdjListOut()) {
if (edge == cur.e) continue;
C newC = costFunc(cur.e, cur.e->getFrom(), edge);
if (costFunc.inf() <= newC) continue;
newC = cur.d + newC;
if (newC < cur.d) continue; // cost overflow!
if (costFunc.inf() <= newC) continue;
const C& h = heurFunc(edge, to);
if (costFunc.inf() <= h) continue;
const C& newH = newC + h;
if (newH < newC) continue; // cost overflow!
pq.push(newH, {edge, cur.e, cur.e->getFrom(), newC});
}
}
for (const auto edge : cur.e->getTo()->getAdjListOut()) {
if (edge == cur.e) continue;
C newC = costFunc(cur.e, cur.e->getTo(), edge);
if (costFunc.inf() <= newC) continue;
newC = cur.d + newC;
if (newC < cur.d) continue; // cost overflow!
if (costFunc.inf() <= newC) continue;
const C& h = heurFunc(edge, to);
if (costFunc.inf() <= h) continue;
const C& newH = newC + h;
if (newH < newC) continue; // cost overflow!
pq.push(newH, {edge, cur.e, cur.e->getTo(), newC});
}
}
// _____________________________________________________________________________
template <typename N, typename E, typename C>
void EDijkstra::buildPath(Edge<N, E>* curE, const Settled<N, E, C>& settled,
NList<N, E>* resNodes, EList<N, E>* resEdges) {
const RouteEdge<N, E, C>* curEdge = &settled.find(curE)->second;
if (resNodes) resNodes->push_back(curEdge->e->getOtherNd(curEdge->n));
while (resNodes || resEdges) {
if (resNodes && curEdge->n) resNodes->push_back(curEdge->n);
if (resEdges) resEdges->push_back(curEdge->e);
if (!curEdge->parent) break;
curEdge = &settled.find(curEdge->parent)->second;
}
}
// _____________________________________________________________________________
template <typename N, typename E, typename C>
void EDijkstra::buildPathInit(Edge<N, E>* curE,
const SettledInit<N, E, C>& settled,
NList<N, E>* resNodes, EList<N, E>* resEdges) {
const RouteEdgeInit<N, E, C>* curEdge = &settled.find(curE)->second;
if (resNodes) resNodes->push_back(curEdge->e->getOtherNd(curEdge->n));
while (resNodes || resEdges) {
if (resNodes && curEdge->n) resNodes->push_back(curEdge->n);
if (resEdges) resEdges->push_back(curEdge->e);
if (!curEdge->parent) break;
curEdge = &settled.find(curEdge->parent)->second;
}
}