Basic Priority Queue with modifykey implementation with std::map

lib/graph/priority_queue.hpp

@@ -38,12 +38,17 @@ public:
   void pop() { m_map.erase(m_map.begin()); }
   void push(const Key& key, const T& value) { m_map.emplace(key, value); }
   void modifyKey(const T& value, const Key& diff) {
-    auto it = std::find_if(m_map.begin(), m_map.end(), [&value](const std::pair<const int, std::string> & p) { return p.second == value; } );
+    auto it = std::find_if(m_map.begin(), m_map.end(), [&value](const std::pair<const Key, T> & p) { return p.second == value; } );
     Key key = it->first; // take a copy
     m_map.erase(it);
     m_map.emplace(key + diff, value);
   }
 
+  bool contains(const T& value) const {
+     auto it = std::find_if(m_map.begin(), m_map.end(), [&value](const std::pair<const Key, T> & p) { return p.second == value; } );
+     return it != m_map.end();
+  }
+
 private:
   std::map<Key, T, Compare, Allocator> m_map;
 };

test/graph/test_priority_queue.cpp

@@ -0,0 +1,105 @@
+#include <graph/priority_queue.hpp>
+
+#include "../catch.hpp"
+
+#include "fixture.hpp"
+
+
+
+TEST_CASE("Priority queue", "[priority_queue][data_structure]" ) {
+
+typedef float W;
+typedef float2 V;
+typedef std::pair<W, V> P;
+
+  SECTION("empty") {
+    PriorityQueue<W, V> pq;
+
+    REQUIRE( pq.size() == 0 );
+    REQUIRE( pq.empty() == true );
+  }
+
+  SECTION("One element") {
+    PriorityQueue<W, V> pq;
+    const V f2(1.0f, 1.0f);
+    pq.push(1.0f, f2);
+
+    REQUIRE( pq.size() == 1 );
+    REQUIRE( pq.empty() == false );
+    REQUIRE( pq.contains(f2) == true );
+
+    P p = pq.top();
+    REQUIRE( p.second == f2 );
+
+    pq.pop();
+    REQUIRE( pq.size() == 0 );
+    REQUIRE( pq.empty() == true );
+  }
+
+  SECTION("Multiple elements") {
+    PriorityQueue<W, V> pq;
+    const V f2_1(1.0f, 1.0f);
+    const V f2_2(2.0f, 2.0f);
+    const V f2_3(3.0f, 3.0f);
+
+    pq.push(3.0f, f2_3);
+    pq.push(1.0f, f2_1);
+    pq.push(2.0f, f2_2);
+
+    REQUIRE( pq.size() == 3 );
+    REQUIRE( pq.empty() == false );
+    REQUIRE( pq.contains(f2_1) == true );
+    REQUIRE( pq.contains(f2_2) == true );
+    REQUIRE( pq.contains(f2_3) == true );
+
+    P p1 = pq.top();
+    pq.pop();
+    REQUIRE( p1.first == 1.0f );
+    REQUIRE( p1.second == f2_1 );
+    REQUIRE( pq.size() == 2 );
+
+    P p2 = pq.top();
+    pq.pop();
+    REQUIRE( p2.first == 2.0f );
+    REQUIRE( p2.second == f2_2 );
+    REQUIRE( pq.size() == 1 );
+
+    P p3 = pq.top();
+    pq.pop();
+    REQUIRE( p3.first == 3.0f );
+    REQUIRE( p3.second == f2_3 );
+
+    REQUIRE( pq.size() == 0 );
+    REQUIRE( pq.empty() == true );
+  }
+
+  SECTION("Modify key") {
+    PriorityQueue<W, V> pq;
+    const V f2_1(1.0f, 1.0f);
+    const V f2_2(2.0f, 2.0f);
+    const V f2_3(3.0f, 3.0f);
+
+    pq.push(3.0f, f2_3);
+    pq.push(1.0f, f2_1);
+    pq.push(2.0f, f2_2);
+
+    pq.modifyKey(f2_1, +3.0f);
+    pq.modifyKey(f2_3, -2.0f);
+
+    P p1 = pq.top();
+    pq.pop();
+    REQUIRE( p1.first == 1.0f );
+    REQUIRE( p1.second == f2_3 );
+
+    P p2 = pq.top();
+    pq.pop();
+    REQUIRE( p2.first == 2.0f );
+    REQUIRE( p2.second == f2_2 );
+
+    P p3 = pq.top();
+    pq.pop();
+    REQUIRE( p3.first == 4.0f );
+    REQUIRE( p3.second == f2_1 );
+  }
+
+}