in_time, out_time;
diff --git a/graph/connected_components.cpp b/graph/connected_components.cpp
index e53dbf424..06bb1ee50 100644
--- a/graph/connected_components.cpp
+++ b/graph/connected_components.cpp
@@ -15,9 +15,9 @@
*
* Example - Here is graph with 3 connected components
*
- * 3 9 6 8
+ * 1 4 5 8
* / \ / / \ / \
- * 2---4 2 7 3 7
+ * 2---3 6 7 9 10
*
* first second third
* component component component
@@ -26,97 +26,123 @@
*/
#include
+#include
#include
#include
-using std::vector;
-
/**
- * Class for representing graph as a adjacency list.
+ * @namespace graph
+ * @brief Graph Algorithms
*/
-class graph {
- private:
- /** \brief adj stores adjacency list representation of graph */
- vector> adj;
-
- /** \brief keep track of connected components */
- int connected_components;
-
- void depth_first_search();
- void explore(int, vector &);
-
- public:
- /**
- * \brief Constructor that intiliazes the graph on creation and set
- * the connected components to 0
- */
- explicit graph(int n) : adj(n, vector()) { connected_components = 0; }
-
- void addEdge(int, int);
-
- /**
- * \brief Function the calculates the connected compoents in the graph
- * by performing the depth first search on graph
- *
- * @return connected_components total connected components in graph
- */
- int getConnectedComponents() {
- depth_first_search();
- return connected_components;
- }
-};
+namespace graph {
/**
- * \brief Function that add edge between two nodes or vertices of graph
+ * @brief Function that add edge between two nodes or vertices of graph
*
- * @param u any node or vertex of graph
- * @param v any node or vertex of graph
+ * @param adj adjacency list of graph.
+ * @param u any node or vertex of graph.
+ * @param v any node or vertex of graph.
*/
-void graph::addEdge(int u, int v) {
- adj[u - 1].push_back(v - 1);
- adj[v - 1].push_back(u - 1);
+void addEdge(std::vector> *adj, int u, int v) {
+ (*adj)[u - 1].push_back(v - 1);
+ (*adj)[v - 1].push_back(u - 1);
}
/**
- * \brief Function that perfoms depth first search algorithm on graph
+ * @brief Utility function for depth first seach algorithm
+ * this function explores the vertex which is passed into.
+ *
+ * @param adj adjacency list of graph.
+ * @param u vertex or node to be explored.
+ * @param visited already visited vertices.
*/
-void graph::depth_first_search() {
- int n = adj.size();
- vector visited(n, false);
+void explore(const std::vector> *adj, int u,
+ std::vector *visited) {
+ (*visited)[u] = true;
+ for (auto v : (*adj)[u]) {
+ if (!(*visited)[v]) {
+ explore(adj, v, visited);
+ }
+ }
+}
+
+/**
+ * @brief Function that perfoms depth first search algorithm on graph
+ * and calculated the number of connected components.
+ *
+ * @param adj adjacency list of graph.
+ *
+ * @return connected_components number of connected components in graph.
+ */
+int getConnectedComponents(const std::vector> *adj) {
+ int n = adj->size();
+ int connected_components = 0;
+ std::vector visited(n, false);
for (int i = 0; i < n; i++) {
if (!visited[i]) {
- explore(i, visited);
+ explore(adj, i, &visited);
connected_components++;
}
}
+ return connected_components;
}
-/**
- * \brief Utility function for depth first seach algorithm
- * this function explores the vertex which is passed into.
- *
- * @param u vertex or node to be explored
- * @param visited already visited vertex
- */
-void graph::explore(int u, vector &visited) {
- visited[u] = true;
- for (auto v : adj[u]) {
- if (!visited[v]) {
- explore(v, visited);
- }
- }
+} // namespace graph
+
+/** Function to test the algorithm */
+void tests() {
+ std::cout << "Running predefined tests..." << std::endl;
+ std::cout << "Initiating Test 1..." << std::endl;
+ std::vector> adj1(9, std::vector());
+ graph::addEdge(&adj1, 1, 2);
+ graph::addEdge(&adj1, 1, 3);
+ graph::addEdge(&adj1, 3, 4);
+ graph::addEdge(&adj1, 5, 7);
+ graph::addEdge(&adj1, 5, 6);
+ graph::addEdge(&adj1, 8, 9);
+
+ assert(graph::getConnectedComponents(&adj1) == 3);
+ std::cout << "Test 1 Passed..." << std::endl;
+
+ std::cout << "Innitiating Test 2..." << std::endl;
+ std::vector> adj2(10, std::vector());
+ graph::addEdge(&adj2, 1, 2);
+ graph::addEdge(&adj2, 1, 3);
+ graph::addEdge(&adj2, 1, 4);
+ graph::addEdge(&adj2, 2, 3);
+ graph::addEdge(&adj2, 3, 4);
+ graph::addEdge(&adj2, 4, 8);
+ graph::addEdge(&adj2, 4, 10);
+ graph::addEdge(&adj2, 8, 10);
+ graph::addEdge(&adj2, 8, 9);
+ graph::addEdge(&adj2, 5, 7);
+ graph::addEdge(&adj2, 5, 6);
+ graph::addEdge(&adj2, 6, 7);
+
+ assert(graph::getConnectedComponents(&adj2) == 2);
+ std::cout << "Test 2 Passed..." << std::endl;
}
/** Main function */
int main() {
- /// creating a graph with 4 vertex
- graph g(4);
+ /// running predefined tests
+ tests();
- /// Adding edges between vertices
- g.addEdge(1, 2);
- g.addEdge(3, 2);
+ int vertices = int(), edges = int();
+ std::cout << "Enter the number of vertices : ";
+ std::cin >> vertices;
+ std::cout << "Enter the number of edges : ";
+ std::cin >> edges;
- /// printing the connected components
- std::cout << g.getConnectedComponents();
+ std::vector> adj(vertices, std::vector());
+
+ int u = int(), v = int();
+ while (edges--) {
+ std::cin >> u >> v;
+ graph::addEdge(&adj, u, v);
+ }
+
+ int cc = graph::getConnectedComponents(&adj);
+ std::cout << cc << std::endl;
return 0;
}
diff --git a/graph/cycle_check_directed_graph.cpp b/graph/cycle_check_directed_graph.cpp
index a9e4f2c8b..c991730c0 100644
--- a/graph/cycle_check_directed_graph.cpp
+++ b/graph/cycle_check_directed_graph.cpp
@@ -1,313 +1,57 @@
-/**
- * @file cycle_check_directed graph.cpp
- *
- * @brief BFS and DFS algorithms to check for cycle in a directed graph.
- *
- * @author [Anmol3299](mailto:mittalanmol22@gmail.com)
- *
- */
+#include
+#include
+#include
+using std::vector;
+using std::pair;
-#include // for std::cout
-#include