Multipurpose graph program added

Graph bfs dfs topological_sort.cpp

@@ -0,0 +1,126 @@
+#include<bits/stdc++.h>
+using namespace std;
+
+void addEdge(vector<int> adj[], int u, int v)
+{
+	adj[u].push_back(v);
+
+}
+
+void printGraph(vector<int> adj[], int V)
+{
+	cout<<"normal graph"<<endl;
+	for(int i=0;i<V;i++)
+	{
+		for(auto x:adj[i])
+		{
+			cout<<x<<" ";
+		}
+		cout<<endl;
+	}
+
+
+}
+
+void bfs(vector<int> adj[], int V)
+{
+	queue<int> q;
+	bool visited[V]={false};
+	q.push(0);
+	cout<<"bfs"<<" ";
+	cout<<0<<" ";
+	visited[0]=true;
+	while(!q.empty())
+	{
+		int s=q.front();
+		q.pop();
+		for(auto x:adj[s])
+		{
+			if(!visited[x])
+			{
+				cout<<x<<" ";
+				visited[x]=true;
+				q.push(x);
+			}
+		}
+	}
+	cout<<endl;
+}
+
+void dfs(vector<int> adj[], int e, vector<bool> &visited)
+{
+	cout<<e<<" ";
+	visited[e]=true;
+	for(auto v:adj[e])
+	{
+		if(!visited[v])
+		{
+			//visited[v]=true;
+			dfs(adj,v,visited);
+		}
+		else continue;
+	}
+	return;
+}
+
+void solve(vector<int> adj[], vector<bool> &visited, stack<int> &s, int e)
+{
+    visited[e]=true;
+    vector<int>::iterator itr;
+
+    for(itr=adj[e].begin();itr!=adj[e].end();itr++)
+    {
+        if(!visited[*itr]) solve(adj,visited,s,*itr);
+    }
+    s.push(e);
+    return;
+}
+
+vector<int> topoSort(int V, vector<int> adj[]) {
+    vector<bool> visited;
+    stack<int> s;
+    vector<int> v;
+    for(int i=0;i<V;i++) visited.push_back(false);
+
+    for(int i=0;i<V;i++)
+    {
+        if(!visited[i])
+            solve(adj,visited,s,i);
+    }
+    while(!s.empty())
+    {
+    	v.push_back(s.top());
+    	s.pop();
+	}
+    return v;
+}
+
+int main()
+{
+	int V=6;
+	vector<int> adj[V];
+	addEdge(adj, 5, 0);
+	addEdge(adj, 5, 2);
+	addEdge(adj, 2, 3);
+	addEdge(adj, 4, 0);
+	addEdge(adj, 4, 1);
+	addEdge(adj, 1, 3);
+
+	printGraph(adj, V);
+	bfs(adj,V);
+	cout<<"dfs"<<" ";
+	vector<bool> visited;
+	for(int i=0;i<V;i++)
+	{
+		visited.push_back(false);
+	}
+	dfs(adj,0,visited);
+
+	cout<<endl<<"topological sort";
+	vector<int> v=topoSort(V,adj);
+	for(int i=0;i<v.size();i++)
+	{
+		cout<<v[i]<<" ";
+	}
+	return 0;
+}