Merge pull request kothariji#35 from incognito1729/master

Create Topological sort using dfs.cpp

Author: kothariji

Graph/Topological sort using dfs.cpp

@@ -0,0 +1,45 @@
+#include<bits/stdc++.h>
+using namespace std;
+static stack<int> s;
+void addata(vector<int> grph[],int a, int b){
+        grph[a].push_back(b);
+}
+
+void DFS(bool visited[],vector<int> grph[],int i){
+    visited[i]=true;
+    for(int p:grph[i]){
+        if(visited[p]==false){
+            DFS(visited,grph,p);
+        }
+    }
+    s.push(i);
+}
+void topological_sort(vector<int>grph[],int v){
+        bool visited[v];
+        int i;
+        for(i=0;i<v;i++){
+            visited[i]=false;
+        }
+        for(i=0;i<v;i++){
+            if(visited[i]==0){
+                DFS(visited,grph,i);
+            }
+        }
+        while(!s.empty()){
+            cout<<s.top()<<" ";
+            s.pop();
+        }
+}
+int main(){
+    int v,e,a,b;
+    cout<<"Enter the number of vertices of in directed graphs"<<endl;
+    cin>>v;
+    vector<int> grph[v];
+    cout<<"Enter the number of edges in graph"<<endl;
+    cin>>e;
+    for(int i=0;i<e;i++){
+        cin>>a>>b;
+        addata(grph,a,b);
+    }
+    topological_sort(grph,v);
+}