Skip to content

Commit

Permalink
changing output format of Kosaraju algorithm
Browse files Browse the repository at this point in the history
  • Loading branch information
@guru2396
guru2396 committed Oct 18, 2023
1 parent 92fca0a commit 07635df
Show file tree
Hide file tree
Showing 3 changed files with 32 additions and 33 deletions.
19 changes: 11 additions & 8 deletions include/CXXGraph/Graph/Graph.hpp
View file
Original file line number Diff line number Diff line change
Expand Up @@ -3364,36 +3364,39 @@ SCCResult<T> Graph<T>::kosaraju() const {

visited.clear();

std::function<void(shared<const Node<T>>, std::vector<Node<T>> &)>
std::function<void(shared<const Node<T>>, SCCResult<T>, int)>
dfs_helper1 =
[this, &rev, &visited, &dfs_helper1](shared<const Node<T>> source,
std::vector<Node<T>> &comp) {
SCCResult<T> result, int sccLabel) {
// mark the vertex visited
visited[source->getId()] = true;
// Add the current vertex to the strongly connected
// component
comp.push_back(*source);
//comp.push_back(*source);
result.sccMap[source->getId()] = sccLabel;

// travel the neighbors
for (int i = 0; i < rev[source].size(); i++) {
shared<const Node<T>> neighbor = rev[source].at(i).first;
if (visited[neighbor->getId()] == false) {
// make recursive call from neighbor
dfs_helper1(neighbor, comp);
dfs_helper1(neighbor, result, sccLabel);
}
}
};

int sccLabel = 0;
while (st.size() != 0) {
auto rem = st.top();
st.pop();
if (visited[rem->getId()] == false) {
std::vector<Node<T>> comp;
dfs_helper1(rem, comp);
result.stronglyConnectedComps.push_back(comp);
//std::vector<Node<T>> comp;
dfs_helper1(rem, result, sccLabel);
sccLabel++;
//result.stronglyConnectedComps.push_back(comp);
}
}

result.noOfComponents = sccLabel;
result.success = true;
return result;
}
Expand Down
4 changes: 3 additions & 1 deletion include/CXXGraph/Utility/Typedef.hpp
View file
Original file line number Diff line number Diff line change
Expand Up @@ -197,7 +197,9 @@ struct SCCResult_struct {
bool success =
false; // TRUE if the function does not return error, FALSE otherwise
std::string errorMessage = ""; // message of error
Components<T> stronglyConnectedComps;
int noOfComponents = 0;
std::unordered_map<size_t, int> sccMap;
//Components<T> stronglyConnectedComps;
};
template <typename T>
using SCCResult = SCCResult_struct<T>;
Expand Down
42 changes: 18 additions & 24 deletions test/KosarajuTest.cpp
View file
Original file line number Diff line number Diff line change
Expand Up @@ -13,22 +13,16 @@ using std::make_shared;

// helper function to compare strongly connected components (SCC) as computed
// by the algorithm with expected (correct) SCC
void compareComponents(CXXGraph::Components<int>& comp1,
void compareComponents(CXXGraph::SCCResult<int> result,
CXXGraph::Components<int>& comp2) {
ASSERT_EQ(comp1.size(), comp2.size());
ASSERT_EQ(result.noOfComponents, comp2.size());

for (size_t i = 0; i < comp1.size(); ++i) {
std::sort(comp1[i].begin(), comp1[i].end());
std::sort(comp2[i].begin(), comp2[i].end());
for(int i=0;i<comp2.size();i++){
int curComp = result.sccMap[comp2[i][0].getId()];
for(int j=1;j<comp2[i].size();j++){
ASSERT_EQ(result.sccMap[comp2[i][j].getId()], curComp);
}
}

std::sort(comp1.begin(), comp1.end(),
[](auto& c1, auto& c2) { return c1.front() < c2.front(); });

std::sort(comp2.begin(), comp2.end(),
[](auto& c1, auto& c2) { return c1.front() < c2.front(); });

ASSERT_EQ(comp1, comp2);
}

// undirected graph
Expand All @@ -39,8 +33,8 @@ TEST(KosarajuTest, test_1) {
CXXGraph::T_EdgeSet<int> edgeSet;
edgeSet.insert(make_shared<CXXGraph::UndirectedEdge<int>>(edge));
CXXGraph::Graph<int> graph(edgeSet);
auto res = graph.kosaraju();
ASSERT_EQ(res.stronglyConnectedComps.size(), 0);
CXXGraph::SCCResult<int> res = graph.kosaraju();
ASSERT_EQ(res.noOfComponents, 0);
ASSERT_FALSE(res.success);
ASSERT_EQ(res.errorMessage, CXXGraph::ERR_UNDIR_GRAPH);
}
Expand All @@ -55,11 +49,11 @@ TEST(KosarajuTest, test_2) {
edgeSet.insert(make_shared<CXXGraph::DirectedEdge<int>>(edge1));
edgeSet.insert(make_shared<CXXGraph::DirectedEdge<int>>(edge2));
CXXGraph::Graph<int> graph(edgeSet);
auto res = graph.kosaraju();
CXXGraph::SCCResult<int> res = graph.kosaraju();
ASSERT_TRUE(res.success);
ASSERT_EQ(res.errorMessage, "");
ASSERT_EQ(res.stronglyConnectedComps.size(), 1);
ASSERT_EQ(res.stronglyConnectedComps[0].size(), 2);
ASSERT_EQ(res.noOfComponents, 1);
//ASSERT_EQ(res.stronglyConnectedComps[0].size(), 2);
}

// 1 comp, 2 strongly connected comp
Expand All @@ -75,12 +69,12 @@ TEST(KosarajuTest, test_3) {
edgeSet.insert(make_shared<CXXGraph::DirectedEdge<int>>(edge2));
edgeSet.insert(make_shared<CXXGraph::DirectedEdge<int>>(edge3));
CXXGraph::Graph<int> graph(edgeSet);
auto res = graph.kosaraju();
CXXGraph::SCCResult<int> res = graph.kosaraju();
ASSERT_TRUE(res.success);
ASSERT_EQ(res.errorMessage, "");

CXXGraph::Components<int> expectedComponents = {{node1, node2}, {node3}};
compareComponents(res.stronglyConnectedComps, expectedComponents);
compareComponents(res, expectedComponents);
}

// 2 components, 2 strongly connected comps
Expand All @@ -99,12 +93,12 @@ TEST(KosarajuTest, test_4) {
edgeSet.insert(make_shared<CXXGraph::DirectedEdge<int>>(edge3));
edgeSet.insert(make_shared<CXXGraph::DirectedEdge<int>>(edge4));
CXXGraph::Graph<int> graph(edgeSet);
auto res = graph.kosaraju();
CXXGraph::SCCResult<int> res = graph.kosaraju();
ASSERT_TRUE(res.success);
ASSERT_EQ(res.errorMessage, "");
CXXGraph::Components<int> expectedComponents = {{node1, node2},
{node3, node4}};
compareComponents(res.stronglyConnectedComps, expectedComponents);
compareComponents(res, expectedComponents);
}

TEST(KosarajuTest, test_5) {
Expand Down Expand Up @@ -168,7 +162,7 @@ TEST(KosarajuTest, test_5) {
edgeSet.insert(make_shared<CXXGraph::DirectedEdge<int>>(edge21));

CXXGraph::Graph graph(edgeSet);
auto res = graph.kosaraju();
CXXGraph::SCCResult<int> res = graph.kosaraju();
ASSERT_TRUE(res.success);
ASSERT_EQ(res.errorMessage, "");

Expand All @@ -179,5 +173,5 @@ TEST(KosarajuTest, test_5) {
{node8, node9},
{node10, node11, node12, node13}};

compareComponents(res.stronglyConnectedComps, expectedComponents);
compareComponents(res, expectedComponents);
}

0 comments on commit 07635df

Please sign in to comment.