Dxchel/big cycle test

include/CXXGraph/Graph/Graph_decl.h

@@ -24,6 +24,7 @@
 
 #include <cmath>
 #include <cstring>
+#include <cstdint>
 #include <deque>
 #include <fstream>
 #include <functional>

test/CycleCheckTest.cpp

@@ -1,4 +1,7 @@
 #include <memory>
+#include <vector>
+#include <string>
+#include <random>
 
 #include "CXXGraph/CXXGraph.hpp"
 #include "gtest/gtest.h"
@@ -9,6 +12,7 @@ using unique = std::unique_ptr<T>;
 template <typename T>
 using shared = std::shared_ptr<T>;
 
+using std::shared_ptr;
 using std::make_shared;
 using std::make_unique;
 
@@ -151,3 +155,45 @@ TEST(CycleCheckTest, test_8) {
   bool res = graph.isCyclicDirectedGraphBFS();
   ASSERT_EQ(res, true);
 }
+
+TEST(CycleCheckTest, test_2001000) {
+  std::random_device rd;
+  std::mt19937 gen(rd());
+  std::uniform_int_distribution<int> distrib(1, 100);
+
+  std::vector<CXXGraph::Node<int>> nodes;
+  std::vector<CXXGraph::DirectedWeightedEdge<int>> edges;
+  nodes.reserve(2001000);
+  edges.reserve(2001000);
+  CXXGraph::T_EdgeSet<int> edgeSet;
+  int node_i = 1;
+  int edge_i = 1;
+
+  /*
+   * Creates a Tree Graph with a root node in which each level
+   * has one more node than the previous one, having in the end
+   * 2000*2001/2 = 2001000 nodes the form looks as follows:
+   * node1---node3---node6...
+   *     |-node2 |-node5
+   *             |-node4
+   */
+  CXXGraph::Node<int> node(std::to_string(node_i), node_i);
+  nodes.push_back(std::move(node));
+  node_i++;
+  for (int i = 2; i < 2001; i++) {
+    for (int j = 0; j < i; j++) {
+      auto last_i_node = nodes.back();
+      CXXGraph::Node<int> node(std::to_string(node_i), node_i);
+      nodes.push_back(std::move(node));
+      node_i++;
+      CXXGraph::DirectedWeightedEdge<int> edge(std::to_string(edge_i++), last_i_node, nodes.back(), distrib(gen));
+      edgeSet.insert(make_shared<CXXGraph::DirectedWeightedEdge<int>>(std::move(edge)));
+    }
+  }
+  CXXGraph::Graph<int> graph_tree(edgeSet);
+  ASSERT_EQ(graph_tree.isCyclicDirectedGraphBFS(), false);
+  CXXGraph::DirectedWeightedEdge<int> edge(std::to_string(edge_i++), nodes.back(), nodes.front(), distrib(gen));
+  edgeSet.insert(make_shared<CXXGraph::DirectedWeightedEdge<int>>(std::move(edge)));
+  CXXGraph::Graph<int> graph_cycle(std::move(edgeSet));
+  ASSERT_EQ(graph_cycle.isCyclicDirectedGraphBFS(), true);
+}