diff --git a/encompass-cs/Graph/DirectedGraph.cs b/encompass-cs/Graph/DirectedGraph.cs
index b60db0d..c8620f2 100644
--- a/encompass-cs/Graph/DirectedGraph.cs
+++ b/encompass-cs/Graph/DirectedGraph.cs
@@ -89,7 +89,7 @@ namespace Encompass
             }
         }
 
-        public void AddEdges(params Tuple<T, T>[] edges)
+        public void AddEdges(params ValueTuple<T, T>[] edges)
         {
             foreach (var edge in edges)
             {
@@ -174,6 +174,34 @@ namespace Encompass
             return priority.Values.Reverse();
         }
 
+        public IEnumerable<ValueTuple<T, int>> LongestPaths(T source)
+        {
+            var topoSort = TopologicalSort();
+
+            var distances = new Dictionary<T, int>();
+            foreach (var node in Vertices)
+            {
+                distances[node] = int.MaxValue;
+            }
+            distances[source] = 0;
+
+            foreach (var node in topoSort)
+            {
+                if (distances[node] != int.MaxValue)
+                {
+                    foreach (var neighbor in Neighbors(node))
+                    {
+                        if (distances[neighbor] > distances[node] + 1)
+                        {
+                            distances[neighbor] = distances[node] + 1;
+                        }
+                    }
+                }
+            }
+
+            return distances.Select((pair) => (pair.Key, pair.Value));
+        }
+
         public IEnumerable<IEnumerable<T>> StronglyConnectedComponents()
         {
             var preorder = new Dictionary<T, uint>();
diff --git a/test/DirectedGraphTest.cs b/test/DirectedGraphTest.cs
index 2a3731e..b4eca48 100644
--- a/test/DirectedGraphTest.cs
+++ b/test/DirectedGraphTest.cs
@@ -47,10 +47,10 @@ namespace Tests
             var myGraph = new DirectedGraph<int>();
             myGraph.AddVertices(1, 2, 3, 4);
             myGraph.AddEdges(
-                Tuple.Create(1, 2),
-                Tuple.Create(2, 3),
-                Tuple.Create(2, 4),
-                Tuple.Create(3, 4)
+                (1, 2),
+                (2, 3),
+                (2, 4),
+                (3, 4)
             );
 
             Assert.That(myGraph.Neighbors(1), Does.Contain(2));
@@ -66,10 +66,10 @@ namespace Tests
             var myGraph = new DirectedGraph<int>();
             myGraph.AddVertices(1, 2, 3, 4);
             myGraph.AddEdges(
-                Tuple.Create(1, 2),
-                Tuple.Create(2, 3),
-                Tuple.Create(2, 4),
-                Tuple.Create(3, 4)
+                (1, 2),
+                (2, 3),
+                (2, 4),
+                (3, 4)
             );
 
             myGraph.RemoveEdge(2, 3);
@@ -84,10 +84,10 @@ namespace Tests
             var myGraph = new DirectedGraph<int>();
             myGraph.AddVertices(1, 2, 3, 4);
             myGraph.AddEdges(
-                Tuple.Create(1, 2),
-                Tuple.Create(2, 3),
-                Tuple.Create(2, 4),
-                Tuple.Create(3, 4)
+                (1, 2),
+                (2, 3),
+                (2, 4),
+                (3, 4)
             );
 
             myGraph.RemoveVertex(2);
@@ -103,9 +103,9 @@ namespace Tests
             var myGraph = new DirectedGraph<char>();
             myGraph.AddVertices('a', 'b', 'c', 'd');
             myGraph.AddEdges(
-                Tuple.Create('a', 'b'),
-                Tuple.Create('a', 'c'),
-                Tuple.Create('b', 'd')
+                ('a', 'b'),
+                ('a', 'c'),
+                ('b', 'd')
             );
 
             var result = myGraph.NodeDFS();
@@ -129,10 +129,10 @@ namespace Tests
             var simpleGraph = new DirectedGraph<char>();
             simpleGraph.AddVertices('a', 'b', 'c', 'd');
             simpleGraph.AddEdges(
-                Tuple.Create('a', 'b'),
-                Tuple.Create('a', 'c'),
-                Tuple.Create('b', 'a'),
-                Tuple.Create('b', 'd')
+                ('a', 'b'),
+                ('a', 'c'),
+                ('b', 'a'),
+                ('b', 'd')
             );
 
             Assert.That(simpleGraph.TopologicalSort(), Is.EqualTo(new char[] { 'a', 'c', 'b', 'd' }));
@@ -144,14 +144,14 @@ namespace Tests
             var complexGraph = new DirectedGraph<char>();
             complexGraph.AddVertices('a', 'b', 'c', 'd', 'e', 'f', 'g', 't', 'm');
             complexGraph.AddEdges(
-                Tuple.Create('a', 'b'),
-                Tuple.Create('a', 'c'),
-                Tuple.Create('a', 'd'),
-                Tuple.Create('b', 'f'),
-                Tuple.Create('b', 'g'),
-                Tuple.Create('c', 'g'),
-                Tuple.Create('e', 't'),
-                Tuple.Create('t', 'm')
+                ('a', 'b'),
+                ('a', 'c'),
+                ('a', 'd'),
+                ('b', 'f'),
+                ('b', 'g'),
+                ('c', 'g'),
+                ('e', 't'),
+                ('t', 'm')
             );
 
             Assert.That(
@@ -160,16 +160,41 @@ namespace Tests
             );
         }
 
+        [Test]
+        public void LongestPaths()
+        {
+            var graph = new DirectedGraph<char>();
+            graph.AddVertices('r', 's', 't', 'x', 'y', 'z');
+            graph.AddEdges(
+                ('r', 's'),
+                ('r', 't'),
+                ('s', 'x'),
+                ('s', 't'),
+                ('t', 'y'),
+                ('t', 'x'),
+                ('x', 'y'),
+                ('y', 'z')
+            );
+
+            var result = graph.LongestPaths('r');
+            result.Should().Contain(('r', 0));
+            result.Should().Contain(('s', 1));
+            result.Should().Contain(('t', 1));
+            result.Should().Contain(('x', 2));
+            result.Should().Contain(('y', 2));
+            result.Should().Contain(('z', 3));
+        }
+
         [Test]
         public void StronglyConnectedComponentsSimple()
         {
             var simpleGraph = new DirectedGraph<int>();
             simpleGraph.AddVertices(1, 2, 3);
             simpleGraph.AddEdges(
-                Tuple.Create(1, 2),
-                Tuple.Create(2, 3),
-                Tuple.Create(3, 2),
-                Tuple.Create(2, 1)
+                (1, 2),
+                (2, 3),
+                (3, 2),
+                (2, 1)
             );
 
             var result = simpleGraph.StronglyConnectedComponents();
@@ -185,12 +210,12 @@ namespace Tests
             var mediumGraph = new DirectedGraph<int>();
             mediumGraph.AddVertices(1, 2, 3, 4);
             mediumGraph.AddEdges(
-                Tuple.Create(1, 2),
-                Tuple.Create(1, 3),
-                Tuple.Create(1, 4),
-                Tuple.Create(4, 2),
-                Tuple.Create(3, 4),
-                Tuple.Create(2, 3)
+                (1, 2),
+                (1, 3),
+                (1, 4),
+                (4, 2),
+                (3, 4),
+                (2, 3)
             );
 
             var result = mediumGraph.StronglyConnectedComponents();
@@ -208,18 +233,18 @@ namespace Tests
             var complexGraph = new DirectedGraph<int>();
             complexGraph.AddVertices(1, 2, 3, 4, 5, 6, 7, 8);
             complexGraph.AddEdges(
-                Tuple.Create(1, 2),
-                Tuple.Create(2, 3),
-                Tuple.Create(2, 8),
-                Tuple.Create(3, 4),
-                Tuple.Create(3, 7),
-                Tuple.Create(4, 5),
-                Tuple.Create(5, 3),
-                Tuple.Create(5, 6),
-                Tuple.Create(7, 4),
-                Tuple.Create(7, 6),
-                Tuple.Create(8, 1),
-                Tuple.Create(8, 7)
+                (1, 2),
+                (2, 3),
+                (2, 8),
+                (3, 4),
+                (3, 7),
+                (4, 5),
+                (5, 3),
+                (5, 6),
+                (7, 4),
+                (7, 6),
+                (8, 1),
+                (8, 7)
             );
 
             var result = complexGraph.StronglyConnectedComponents();
@@ -239,11 +264,11 @@ namespace Tests
             var myGraph = new DirectedGraph<int>();
             myGraph.AddVertices(1, 2, 3, 4);
             myGraph.AddEdges(
-                Tuple.Create(1, 1),
-                Tuple.Create(1, 2),
-                Tuple.Create(2, 3),
-                Tuple.Create(2, 1),
-                Tuple.Create(3, 4)
+                (1, 1),
+                (1, 2),
+                (2, 3),
+                (2, 1),
+                (3, 4)
             );
 
             var clone = myGraph.Clone();
@@ -260,11 +285,11 @@ namespace Tests
             var myGraph = new DirectedGraph<int>();
             myGraph.AddVertices(1, 2, 3, 4);
             myGraph.AddEdges(
-                Tuple.Create(1, 1),
-                Tuple.Create(1, 2),
-                Tuple.Create(2, 3),
-                Tuple.Create(2, 1),
-                Tuple.Create(3, 4)
+                (1, 1),
+                (1, 2),
+                (2, 3),
+                (2, 1),
+                (3, 4)
             );
 
             var subGraph = myGraph.SubGraph(1, 2, 3);
@@ -280,13 +305,13 @@ namespace Tests
             var myGraph = new DirectedGraph<int>();
             myGraph.AddVertices(0, 1, 2);
             myGraph.AddEdges(
-                Tuple.Create(0, 0),
-                Tuple.Create(0, 1),
-                Tuple.Create(0, 2),
-                Tuple.Create(1, 2),
-                Tuple.Create(2, 0),
-                Tuple.Create(2, 1),
-                Tuple.Create(2, 2)
+                (0, 0),
+                (0, 1),
+                (0, 2),
+                (1, 2),
+                (2, 0),
+                (2, 1),
+                (2, 2)
             );
 
             var result = myGraph.SimpleCycles();
@@ -311,20 +336,20 @@ namespace Tests
             var myGraph = new DirectedGraph<int>();
             myGraph.AddVertices(0, 1, 2, 3, 4, 5, 6, 7, 8, 9);
             myGraph.AddEdges(
-                Tuple.Create(0, 1),
-                Tuple.Create(1, 2),
-                Tuple.Create(2, 3),
-                Tuple.Create(3, 0),
-                Tuple.Create(0, 3),
-                Tuple.Create(3, 4),
-                Tuple.Create(4, 5),
-                Tuple.Create(5, 0),
-                Tuple.Create(0, 1),
-                Tuple.Create(1, 6),
-                Tuple.Create(6, 7),
-                Tuple.Create(7, 8),
-                Tuple.Create(8, 0),
-                Tuple.Create(8, 9)
+                (0, 1),
+                (1, 2),
+                (2, 3),
+                (3, 0),
+                (0, 3),
+                (3, 4),
+                (4, 5),
+                (5, 0),
+                (0, 1),
+                (1, 6),
+                (6, 7),
+                (7, 8),
+                (8, 0),
+                (8, 9)
             );
 
             var result = myGraph.SimpleCycles();
@@ -348,10 +373,10 @@ namespace Tests
             var myGraph = new DirectedGraph<int>();
             myGraph.AddVertices(1, 2, 3, 4);
             myGraph.AddEdges(
-                Tuple.Create(1, 2),
-                Tuple.Create(2, 3),
-                Tuple.Create(3, 1),
-                Tuple.Create(3, 4)
+                (1, 2),
+                (2, 3),
+                (3, 1),
+                (3, 4)
             );
 
             Assert.That(myGraph.Cyclic(), Is.True);
@@ -363,9 +388,9 @@ namespace Tests
             var myGraph = new DirectedGraph<int>();
             myGraph.AddVertices(1, 2, 3, 4);
             myGraph.AddEdges(
-                Tuple.Create(1, 2),
-                Tuple.Create(2, 3),
-                Tuple.Create(3, 4)
+                (1, 2),
+                (2, 3),
+                (3, 4)
             );
 
             Assert.That(myGraph.Cyclic(), Is.False);