diff --git a/algorithm/italiano.h b/algorithm/italiano.h index b151694..662fe66 100644 --- a/algorithm/italiano.h +++ b/algorithm/italiano.h @@ -3,12 +3,11 @@ #include "algorithm/roditty_zwick.h" #include "algorithm/tarjan.h" -#include "tree/breadth_first_tree.h" +#include "graph/breadth_first_tree.h" #include using namespace graph; -using namespace tree; namespace algo { @@ -25,60 +24,59 @@ public: private: Digraph G; - // Connect each vertex with its representative SCC - std::map> TC; + // Transitive closure matrix, used to answer reachability queries in O(1) + std::map> TC; - // Reachability trees - std::map> RT; + // Each vertex's reachability tree + std::map> RT; // Incoming / Outgoing edges struct Edges { - std::forward_list Ein; - std::forward_list Eout; + std::forward_list inc; + std::forward_list out; }; - std::map, Edges> E; + std::map E; }; template void Italiano::init() { - + for (const auto& u : std::views::keys(G.adjMatrix)) { + for (const auto& v : G.adjMatrix[u]) { + E[v].inc.push_front(u); + E[u].out.push_front(v); + TC[u][v] = false; + } + RT[u] = BreadthFirstTree(G, u); + TC[u][u] = true; + for (const auto& v : std::views::keys(RT[u].adjMatrix)) { + TC[u][v] = true; + } + } } template bool Italiano::query(const T& u, const T& v) { - return TC[u] == TC[v]; + return TC[u][v]; } template void Italiano::remove(const T& u, const T& v) { - - for (const auto& w : G.adjMatrix) { - // Check if (u,v) edge of T(w) || p(w,v) points to (u,v) - - // If yes => set p(w, v) to point to the next edge (u',v) in Ein(v) - // If (u,v) the last edge, then set it to point to null - - // If T(w) contains u' then the new edge reconnects v to T(w) - // As this needs to be checked, we set R(w) <- {v} - - // If (u,v) is not edge of T(w) or is the last edge in Ein(v), R(w) <- phi - - // Remove (u,v) from Eout(u) and Ein(v) + std::map> R; + for (const auto& w : std::views::keys(G.adjMatrix)) { + if (RT[w].contains(u, v)) { + R[w].insert(v); + } + E[u].inc.remove(v); + E[u].out.remove(u); + G.remove(u, v); } - for (const auto& w : G.adjMatrix) { - - // Check tentative pointers of the vertices in R(w). - // While there is a vertex x in R(w), scan the edges in Ein(x), starting - // from the edge pointed to by p(w,x), until an edge (u',x) for which - // p(w,u') != null is found or Ein(x) is exhausted. - - // If such edge is found, x is removed from R(w). - // If the list is exhausted, set p(w,x) to null and M(w,x) to 0 - - // Then scan all Eout(x). If (x,x') is tree edge, add x' to R(w) - } + //for (const auto& w : std::views::keys(G.adjMatrix)) { + // while (R[w].size() > 0) { + // auto pop = R[w]. + // } + //} } } // namespace algo diff --git a/test/decremental_test.cc b/test/decremental_test.cc index 8f839f6..dc741cc 100644 --- a/test/decremental_test.cc +++ b/test/decremental_test.cc @@ -93,11 +93,16 @@ TEST_SUITE("Decremental algorithms") { REQUIRE_EQ(G.adjMatrix.size(), 13); - algo::Italiano rz(G); - rz.init(); + algo::Italiano italiano(G); + italiano.init(); SUBCASE("Italiano::query") { - + CHECK_EQ(italiano.query(1, 13), true); + CHECK_EQ(italiano.query(6, 10), true); + CHECK_EQ(italiano.query(9, 11), true); + CHECK_EQ(italiano.query(8, 2), false); + CHECK_EQ(italiano.query(9, 3), false); + CHECK_EQ(italiano.query(9, 8), false); } SUBCASE("Italiano::remove") { @@ -134,8 +139,8 @@ TEST_SUITE("Decremental algorithms") { REQUIRE_EQ(G.adjMatrix.size(), 13); - algo::Frigioni rz(G); - rz.init(); + algo::Frigioni frigioni(G); + frigioni.init(); SUBCASE("Frigioni::query") {