Add example of object graph traversal algorithms

+ Using pseudocode examples from MIT Intro to Algorithms
2021-06-28 10:12:19 -04:00
parent 21ed349c39
commit 5d37db1ce2
4 changed files with 309 additions and 0 deletions
--- a/cpp/algorithms/graphs/object/graph.cpp
+++ b/cpp/algorithms/graphs/object/graph.cpp
@@ -0,0 +1,101 @@
+/*##############################################################################
+## Author: Shaun Reed                                                         ##
+## Legal: All Content (c) 2021 Shaun Reed, all rights reserved                ##
+## About: An example of an object graph implementation                        ##
+##        Algorithms in this example are found in MIT Intro to Algorithms     ##
+##                                                                            ##
+## Contact: shaunrd0@gmail.com  | URL: www.shaunreed.com | GitHub: shaunrd0   ##
+################################################################################
+*/
+
+#include "lib-graph.hpp"
+
+
+int main (const int argc, const char * argv[])
+{
+  // We could initialize the graph with some localNodes...
+  std::map<int, std::set<int>> localNodes{
+      {1, {2, 5}}, // Node 1
+      {2, {1, 6}}, // Node 2
+      {3, {4, 6, 7}},
+      {4, {3, 7, 8}},
+      {5, {1}},
+      {6, {2, 3, 7}},
+      {7, {3, 4, 6, 8}},
+      {8, {4, 6}},
+  };
+//  Graph bfsGraph(localNodes);
+
+//  Graph testGraph(
+//      {
+//          {Node(1, {2, 5})},
+////          {Node(1, {2, 5})},
+//       }
+//  )
+
+
+  std::cout << "\n\n##### Breadth First Search #####\n";
+  // Or we could use an initializer list...
+  // Initialize a example graph for Breadth First Search
+  Graph bfsGraph (
+      {
+          {Node(1, {2, 5})}, // Node 1
+          {Node(2, {1, 6})}, // Node 2...
+          {Node(3, {4, 6, 7})},
+          {Node(4, {3, 7, 8})},
+          {Node(5, {1})},
+          {Node(6, {2, 3, 7})},
+          {Node(7, {3, 4, 6, 8})},
+          {Node(8, {4, 6})},
+      }
+  );
+  // The graph traversed in this example is seen in MIT Intro to Algorithms
+  // + Chapter 22, Figure 22.3 on BFS
+  auto iter = bfsGraph.nodes_.begin();
+  std::advance(iter, 1);
+  bfsGraph.BFS(*iter);
+
+
+  std::cout << "\n\n##### Depth First Search #####\n";
+  // Initialize an example graph for Depth First Search
+  Graph dfsGraph (
+      {
+          {1, {2, 4}},
+          {2, {5}},
+          {3, {5, 6}},
+          {4, {2}},
+          {5, {4}},
+          {6, {6}},
+      }
+  );
+  // The graph traversed in this example is seen in MIT Intro to Algorithms
+  // + Chapter 22, Figure 22.4 on DFS
+  dfsGraph.DFS();
+
+
+  std::cout << "\n\n##### Topological Sort #####\n";
+  // Initialize an example graph for Depth First Search
+  Graph topologicalGraph (
+      {
+          {1, {4, 5}},
+          {2, {5}},
+          {3, {}},
+          {4, {5, 7}},
+          {5, {}},
+          {6, {7, 8}},
+          {7, {9}},
+          {8, {9}},
+          {9, {}},
+      }
+  );
+  // The graph traversed in this example is seen in MIT Intro to Algorithms
+  // + Chapter 22, Figure 22.4 on DFS
+  std::vector<Node> order = topologicalGraph.TopologicalSort();
+  std::cout << "\n\nTopological order: ";
+  while (!order.empty()) {
+    std::cout << order.back().number << " ";
+    order.pop_back();
+  }
+  std::cout << std::endl;
+
+}