From 1d7cea86eccd108e6a06e7bfac082ddca77f9978 Mon Sep 17 00:00:00 2001
From: Abhishek Yadav <31253403+AbhiY98@users.noreply.github.com>
Date: Tue, 20 Nov 2018 19:00:46 +0530
Subject: [PATCH 1/2] Added Topological Sorting

---
 Graph/Topological-Sort.cpp | 45 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 45 insertions(+)
 create mode 100644 Graph/Topological-Sort.cpp

diff --git a/Graph/Topological-Sort.cpp b/Graph/Topological-Sort.cpp
new file mode 100644
index 000000000..f05217209
--- /dev/null
+++ b/Graph/Topological-Sort.cpp
@@ -0,0 +1,45 @@
+#include <iostream>
+#include <vector>
+#include <algorithm>
+  using namespace std;
+
+int n , m; // For number of Vertices (V) and number of edges (E)
+vector< vector<int> > G;
+vector<bool> visited;
+vector<int> ans;
+
+void dfs(int v) {
+  visited[v] = true;
+  for (int u : G[v]) {
+    if (!visited[u])
+      dfs(u);
+  }
+  ans.push_back(v);
+}
+ 
+void topological_sort() {
+  visited.assign(n, false);
+  ans.clear();
+  for (int i = 0; i < n; ++i) {
+    if (!visited[i])
+      dfs(i);
+  }
+  reverse(ans.begin(), ans.end());
+}
+int main(){
+  cin >> n >> m;
+  int x , y;
+  G.resize(n , vector<int>());
+  for(int i = 0 ; i < n ; ++i) {
+    cin >> x >> y;
+    x-- , y--; //to convert 1-indexed to 0-indexed
+    G[x].push_back(y);
+  }
+  topological_sort();
+  cout << "Topological Order : \n";
+  for(int v : ans) {
+    cout << v << ' ';
+  }
+  cout << '\n';
+  return 0;
+}

From a8ab996d27ee219cefedc645e28b21f7419d75f3 Mon Sep 17 00:00:00 2001
From: Abhishek Yadav <31253403+AbhiY98@users.noreply.github.com>
Date: Wed, 20 Feb 2019 00:15:38 +0530
Subject: [PATCH 2/2] Update Topological-Sort.cpp

---
 Graph/Topological-Sort.cpp | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/Graph/Topological-Sort.cpp b/Graph/Topological-Sort.cpp
index f05217209..61a4fcd2e 100644
--- a/Graph/Topological-Sort.cpp
+++ b/Graph/Topological-Sort.cpp
@@ -27,18 +27,19 @@ void topological_sort() {
   reverse(ans.begin(), ans.end());
 }
 int main(){
+  cout << "Enter the number of vertices and the number of directed edges\n";
   cin >> n >> m;
   int x , y;
   G.resize(n , vector<int>());
   for(int i = 0 ; i < n ; ++i) {
     cin >> x >> y;
-    x-- , y--; //to convert 1-indexed to 0-indexed
+    x-- , y--; // to convert 1-indexed to 0-indexed
     G[x].push_back(y);
   }
   topological_sort();
   cout << "Topological Order : \n";
   for(int v : ans) {
-    cout << v << ' ';
+    cout << v + 1 << ' '; // converting zero based indexing back to one based.
   }
   cout << '\n';
   return 0;