Finish Tarjan algorithm and add tests

test/algorithm_test.cc

@@ -0,0 +1,73 @@
+#include <doctest/doctest.h>
+
+#include "graph/graph.h"
+using namespace graph;
+#include "algorithm/tarjan.h"
+
+TEST_SUITE("Algorithms") {
+
+  TEST_CASE("Tarjan T_1") {
+
+    Graph<std::uint16_t> G;
+    G.insert(1, 2);
+    G.insert(2, 4);
+    G.insert(2, 3);
+    G.insert(3, 5);
+    G.insert(4, 1);
+    G.insert(5, 7);
+    G.insert(5, 9);
+    G.insert(6, 8);
+    G.insert(7, 3);
+    G.insert(8, 9);
+    G.insert(9, 6);
+
+    REQUIRE_EQ(G.vertices.size(), 9);
+
+    algo::Tarjan<std::uint16_t> tarjan(G);
+    auto result = tarjan.run();
+    
+    std::sort(result.begin(), result.end());
+    std::for_each(result.begin(), result.end(), [&](std::vector<std::uint16_t>& row) {
+      std::sort(row.begin(), row.end());
+    });
+    
+    std::vector<std::vector<std::uint16_t>> expected{
+      {1, 2, 4},
+      {3, 5, 7},
+      {6, 8, 9}
+    };
+
+    CHECK_EQ(expected, result);
+  }
+
+  TEST_CASE("Tarjan T_2") {
+
+    Graph<std::uint16_t> G;
+    G.insert(1, 4);
+    G.insert(1, 2);
+    G.insert(2, 5);
+    G.insert(3, 1);
+    G.insert(4, 3);
+    G.insert(4, 6);
+    G.insert(5, 7);
+    G.insert(6, 3);
+    G.insert(7, 2);
+
+    REQUIRE_EQ(G.vertices.size(), 7);
+
+    algo::Tarjan<std::uint16_t> tarjan(G);
+    auto result = tarjan.run();
+
+    std::sort(result.begin(), result.end());
+    std::for_each(result.begin(), result.end(), [&](std::vector<std::uint16_t>& row) {
+      std::sort(row.begin(), row.end());
+    });
+    
+    std::vector<std::vector<std::uint16_t>> expected{
+      {1, 3, 4, 6},
+      {2, 5, 7}
+    };
+
+    CHECK_EQ(expected, result);
+  }
+}