Create topological_sort.cpp

dsa-roadmaps/Beginners/Algorithms/Graphs/topological_sort.cpp

@@ -0,0 +1,80 @@
+#include <bits/stdc++.h>
+using namespace std;
+
+#define IOS ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);
+#define endl "\n"
+#define int long long
+#define pb push_back
+#define pf push_front
+
+//Sorting the graph in topological order
+
+class Graph
+{
+    map<int, list<int>> l;
+
+    public:
+    void addEdge(int x, int y)
+    {
+        l[x].pb(y);
+    }
+
+    void dfs_helper(int node, map<int, bool> &visited, list<int> &ordering)
+    {
+      visited[node] = true;
+
+      for(auto nbrs: l[node])
+      {
+          if(!visited[nbrs])
+          {
+              visited[nbrs] = true;
+              dfs_helper(nbrs, visited, ordering);
+          }
+      }
+
+      ordering.pf(node);
+    }
+
+    void dfs(int src)
+    {
+        map<int, bool> visited;
+        list<int> ordering;
+        for(auto pair: l)
+        {
+            auto node = pair.first;
+            visited[node] = false;
+        }
+
+        for(auto pair: l)
+        {
+            auto node = pair.first;
+            if(!visited[node])
+            {
+                dfs_helper(node, visited, ordering);
+            }
+        }
+
+        for(auto items: ordering)
+        {
+            cout<<items<<" ";
+        }
+    }
+};
+
+int32_t main()
+{
+  IOS;
+  Graph g;
+  g.addEdge(1,2);
+  g.addEdge(1,3);
+  g.addEdge(1,4);
+  g.addEdge(3,5);
+  g.addEdge(4,5);
+  g.addEdge(5,7);
+  g.addEdge(6,7);
+  g.dfs(1);
+
+
+  return 0;
+}
+