Ticket #302: 302-crossrefmap-fix-e8254acfab7d.patch

lemon/maps.h

@@ -1903 +1903 @@
 
   /// This class provides simple invertable graph maps.
   /// It wraps a standard graph map (\c NodeMap, \c ArcMap or \c EdgeMap)
-  /// and if a key is set to a new value then stores it in the inverse map.
+  /// and if a key is set to a new value, then stores it in the inverse map.
   ///
   /// The values of the map can be accessed
   /// with stl compatible forward iterator.
@@ -1922 +1922 @@
     typedef typename ItemSetTraits<GR, K>::
       template Map<V>::Type Map;
 
-    typedef std::map<V, K> Container;
+    typedef std::multimap<V, K> Container;
     Container _inv_map;
 
   public:
@@ -1947 +1947 @@
     /// This iterator is an stl compatible forward
     /// iterator on the values of the map. The values can
     /// be accessed in the <tt>[beginValue, endValue)</tt> range.
+    /// They are considered with multiplicity, so each value is
+    /// traversed for each item it is assigned to.
     class ValueIterator
       : public std::iterator<std::forward_iterator_tag, Value> {
       friend class CrossRefMap;
@@ -1999 +2001 @@
     /// Sets the value associated with the given key.
     void set(const Key& key, const Value& val) {
       Value oldval = Map::operator[](key);
-      typename Container::iterator it = _inv_map.find(oldval);
-      if (it != _inv_map.end() && it->second == key) {
-        _inv_map.erase(it);
+      typename Container::iterator it;
+      for (it = _inv_map.equal_range(oldval).first;
+           it != _inv_map.equal_range(oldval).second; ++it) {
+        if (it->second == key) {
+          _inv_map.erase(it);
+          break;
+        }
       }
       _inv_map.insert(std::make_pair(val, key));
       Map::set(key, val);
@@ -2015 +2021 @@
       return Map::operator[](key);
     }
 
-    /// \brief Gives back the item by its value.
+    /// \brief Gives back an item by its value.
     ///
-    /// Gives back the item by its value.
-    Key operator()(const Value& key) const {
-      typename Container::const_iterator it = _inv_map.find(key);
+    /// This function gives back an item that is assigned to
+    /// the given value or \c INVALID if no such item exists.
+    /// If there are more items with the same associated value,
+    /// only one of them is returned.
+    Key operator()(const Value& val) const {
+      typename Container::const_iterator it = _inv_map.find(val);
       return it != _inv_map.end() ? it->second : INVALID;
     }
+    
+    /// \brief Returns the number of items with the given value.
+    ///
+    /// This function returns the number of items with the given value
+    /// associated with it.
+    int count(const Value &val) const {
+      return _inv_map.count(val);
+    }
 
   protected:
 
@@ -2031 +2048 @@
     /// \c AlterationNotifier.
     virtual void erase(const Key& key) {
       Value val = Map::operator[](key);
-      typename Container::iterator it = _inv_map.find(val);
-      if (it != _inv_map.end() && it->second == key) {
-        _inv_map.erase(it);
+      typename Container::iterator it;
+      for (it = _inv_map.equal_range(val).first;
+           it != _inv_map.equal_range(val).second; ++it) {
+        if (it->second == key) {
+          _inv_map.erase(it);
+          break;
+        }
       }
       Map::erase(key);
     }
@@ -2045 +2066 @@
     virtual void erase(const std::vector<Key>& keys) {
       for (int i = 0; i < int(keys.size()); ++i) {
         Value val = Map::operator[](keys[i]);
-        typename Container::iterator it = _inv_map.find(val);
-        if (it != _inv_map.end() && it->second == keys[i]) {
-          _inv_map.erase(it);
+        typename Container::iterator it;
+        for (it = _inv_map.equal_range(val).first;
+             it != _inv_map.equal_range(val).second; ++it) {
+          if (it->second == keys[i]) {
+            _inv_map.erase(it);
+            break;
+          }
         }
       }
       Map::erase(keys);
@@ -2083 +2108 @@
 
       /// \brief Subscript operator.
       ///
-      /// Subscript operator. It gives back the item
-      /// that was last assigned to the given value.
+      /// Subscript operator. It gives back an item
+      /// that is assigned to the given value or \c INVALID
+      /// if no such item exists.
       Value operator[](const Key& key) const {
         return _inverted(key);
       }

test/maps_test.cc

@@ -439 +439 @@
                  CrossRefMap<Graph, Node, double> >();
     
     Graph gr;
-    CrossRefMap<Graph, Node, char> map(gr);
+    typedef CrossRefMap<Graph, Node, char> CRMap;
+    typedef CRMap::ValueIterator ValueIt;
+    CRMap map(gr);
     
     Node n0 = gr.addNode();
     Node n1 = gr.addNode();
@@ -455 +457 @@
           "Wrong CrossRefMap");
     check(map[n2] == 'C' && map('C') == n2 && map.inverse()['C'] == n2,
           "Wrong CrossRefMap");
-          
+    check(map.count('A') == 1 && map.count('B') == 1 && map.count('C') == 1,
+          "Wrong CrossRefMap::count()");
+    
+    ValueIt it = map.beginValue();
+    check(*it++ == 'A' && *it++ == 'B' && *it++ == 'C' &&
+          it == map.endValue(), "Wrong value iterator");
+    
     map.set(n2, 'A');
 
     check(map[n0] == 'A' && map[n1] == 'B' && map[n2] == 'A',
@@ -464 +472 @@
     check(map('B') == n1 && map.inverse()['B'] == n1, "Wrong CrossRefMap");
     check(map('C') == INVALID && map.inverse()['C'] == INVALID,
           "Wrong CrossRefMap");
+    check(map.count('A') == 2 && map.count('B') == 1 && map.count('C') == 0,
+          "Wrong CrossRefMap::count()");
+
+    it = map.beginValue();
+    check(*it++ == 'A' && *it++ == 'A' && *it++ == 'B' &&
+          it == map.endValue(), "Wrong value iterator");
 
     map.set(n0, 'C');
 
     check(map[n0] == 'C' && map[n1] == 'B' && map[n2] == 'A',
           "Wrong CrossRefMap");
-    check(map('A') == INVALID && map.inverse()['A'] == INVALID,
-          "Wrong CrossRefMap");
+    check(map('A') == n2 && map.inverse()['A'] == n2, "Wrong CrossRefMap");
     check(map('B') == n1 && map.inverse()['B'] == n1, "Wrong CrossRefMap");
     check(map('C') == n0 && map.inverse()['C'] == n0, "Wrong CrossRefMap");
+    check(map.count('A') == 1 && map.count('B') == 1 && map.count('C') == 1,
+          "Wrong CrossRefMap::count()");
+
+    it = map.beginValue();
+    check(*it++ == 'A' && *it++ == 'B' && *it++ == 'C' &&
+          it == map.endValue(), "Wrong value iterator");
   }
 
   return 0;