Added basic graph with example

Data Structures/graph.cpp

@@ -0,0 +1,176 @@
+ #include<bits/stdc++.h>
+#include<windows.h>
+#define fr(a,i) for(int i=0;i<a;i++)
+using namespace std;
+
+
+
+class Graph {
+
+  private:
+      int Gid;
+  protected:
+        struct node {
+            vector<node*> links;
+            int id;
+            string data;
+            bool visited;
+        };
+
+    vector<node*> vertices;
+
+  public:
+
+    node * newNode(string x) {
+        node *temp = new node;
+        temp->data = x;
+        temp->id = Gid++;
+        temp->visited = false;
+        vertices.push_back(temp);
+        return temp;
+    }
+
+    void unvisit() {
+        fr(vertices.size(), i) {
+            vertices[i]->visited = false;
+        }
+    }
+    int unvisitedVertices() {
+
+
+        fr(vertices.size(), i) {
+            if(vertices[i]->visited == false) {
+                return i;
+            }
+        }
+        return -1;
+    }
+
+    inline bool linkNotPresent( vector<node*> links, node *blink) {
+        bool notfound = true;
+        fr(links.size(),i) {
+            if(links[i] == blink )
+                notfound = false;
+        }
+        return notfound;
+    }
+
+    int addEdge( string a, string b) {
+        node *anode,*bnode;
+        bool af=false,bf=false;
+        fr(vertices.size(),i) {
+            if( vertices[i]->data == a ) {
+                anode = vertices[i];
+                af =true;
+            }
+            if( vertices[i]->data == b ) {
+                bnode = vertices[i];
+                bf =true;
+            }
+            if( af && bf ) {
+                break;
+            }
+        }
+
+        if( !(anode &&  bnode) ) {
+            return -1;
+        }
+
+        if(linkNotPresent( anode->links, bnode) ) {
+            anode->links.push_back(bnode);
+        }
+        return 1;
+    }
+
+    void printList() {
+        fr( vertices.size(), i) {
+            cout<<vertices[i]->data<<" --->  ";
+            fr( vertices[i]->links.size(), j) {
+                cout<<vertices[i]->links[j]->data<<" , ";
+            }
+            cout<<"\n";
+        }
+    }
+
+    void printDFS(node *temp = NULL) {
+        stack<node*> nodeStack;
+         if(!temp) {
+            unvisit();
+            while(unvisitedVertices() != -1) {
+                int unvisitedVertice = unvisitedVertices();
+                printDFS(vertices[ unvisitedVertice ] );
+            }
+        }
+        else {
+            nodeStack.push(temp);
+            while(!nodeStack.empty()) {
+                node *temp = nodeStack.top();
+                if(!temp->visited)
+                    cout<<temp->data<<" ";
+                temp->visited = true;
+                nodeStack.pop();
+                fr( temp->links.size(), i) {
+                    if(!temp->links[i]->visited) {
+                        nodeStack.push(temp->links[i]);
+                     //   temp->links[i]->visited = true;
+                    }
+                }
+            }
+        }
+    }
+
+    void printBFS(node *temp = NULL) {
+        queue<node*> nodeQueue;
+
+        if(!temp) {
+            unvisit();
+            while(unvisitedVertices() != -1) {
+                int unvisitedVertice = unvisitedVertices();
+                printBFS(vertices[ unvisitedVertice ] );
+            }
+        }
+        else {
+            nodeQueue.push(temp);
+            while(!nodeQueue.empty()) {
+                node *temp = nodeQueue.front();
+                if(!temp->visited)
+                    cout<<temp->data<<" ";
+                temp->visited = true;
+                nodeQueue.pop();
+                fr( temp->links.size(), i){
+                    if(!temp->links[i]->visited) {
+                        nodeQueue.push(temp->links[i]);
+                      //  temp->links[i]->visited = true;
+                    }
+                }
+            }
+        }
+    }
+
+    Graph() {
+        Gid = 0;
+    }
+
+};
+
+int main() {
+    Graph facebook;
+    facebook.newNode("1");
+    facebook.newNode("2");
+    facebook.newNode("3");
+    facebook.newNode("4");
+    facebook.newNode("5");
+    facebook.newNode("6");
+    facebook.newNode("7");
+    //facebook.newNode("sirvani");
+    facebook.addEdge("1","2"); facebook.addEdge("2","1");
+    facebook.addEdge("3","4");
+
+    cout<<" \n list \n";
+    facebook.printList();
+    cout<<" \n bfs \n";
+    facebook.printBFS();
+    cout<<" \n dfs \n";
+    facebook.printDFS();
+    return 0;
+}