Create main.cpp

Author: JawadSher

23 - Graph Data Structure Problems/03 - DFS Traversal in Graph/main.cpp

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+#include <iostream>
+#include <vector>
+#include <stack>
+using namespace std;
+
+class Graph {
+public:
+    vector<vector<int>> adjacencyList;  // Adjacency list representation of the graph
+
+    // Constructor to initialize the graph with the given number of nodes
+    Graph(int totalNodes) {
+        adjacencyList.resize(totalNodes);  // Resize the adjacency list to fit the total nodes
+    }
+
+    // Method to add an edge to the graph
+    void addEdge(int sourceNode, int destinationNode, bool isDirected = false) {
+        adjacencyList[sourceNode].push_back(destinationNode);  // Add destination node to source node's adjacency list
+        if (!isDirected) {
+            adjacencyList[destinationNode].push_back(sourceNode);  // For undirected graph, add the reverse edge
+        }
+    }
+
+    // Recursive DFS implementation
+    void dfsRecursive(int startNode, vector<bool>& visited) {
+        visited[startNode] = true;  // Mark the node as visited
+        cout << startNode << " ";  // Print the visited node
+
+        // Visit all the unvisited neighbors of the current node
+        for (int neighbor : adjacencyList[startNode]) {
+            if (!visited[neighbor]) {
+                dfsRecursive(neighbor, visited);  // Recursively visit the neighbor
+            }
+        }
+    }
+
+    // Iterative DFS implementation using a stack
+    void dfsIterative(int startNode) {
+        vector<bool> visited(adjacencyList.size(), false);  // Keep track of visited nodes
+        stack<int> s;  // Stack to manage the nodes
+
+        s.push(startNode);  // Push the starting node into the stack
+
+        while (!s.empty()) {
+            int currentNode = s.top();  // Get the top node from the stack
+            s.pop();  // Remove it from the stack
+
+            if (!visited[currentNode]) {
+                cout << currentNode << " ";  // Print the current node
+                visited[currentNode] = true;  // Mark it as visited
+            }
+
+            // Push all unvisited neighbors of the current node into the stack
+            for (int neighbor : adjacencyList[currentNode]) {
+                if (!visited[neighbor]) {
+                    s.push(neighbor);
+                }
+            }
+        }
+    }
+};
+
+int main() {
+    int totalNodes = 6;  // Total number of nodes in the graph
+
+    Graph g(totalNodes);  // Create a graph object
+
+    // Adding edges to the graph
+    g.addEdge(0, 1);
+    g.addEdge(0, 2);
+    g.addEdge(1, 3);
+    g.addEdge(1, 4);
+    g.addEdge(2, 5);
+
+    cout << "DFS Traversal (Recursive): ";
+    vector<bool> visited(totalNodes, false);  // Visited array to track nodes
+    g.dfsRecursive(0, visited);  // Perform DFS starting from node 0
+    cout << endl;
+
+    cout << "DFS Traversal (Iterative): ";
+    g.dfsIterative(0);  // Perform iterative DFS starting from node 0
+    cout << endl;
+
+    return 0;
+}