- Add Min() and Max() function to the tree map with test and documentation update

README.md

@@ -400,6 +400,10 @@ func main() {
 	m.Clear()                           // empty
 	m.Empty()                           // true
 	m.Size()                            // 0
+
+    // Other:
+    m.Min() // Returns the minimum key and its value from map.
+    m.Max() // Returns the maximum key and its value from map.
 }
 ```
 

maps/treemap/treemap.go

@@ -73,16 +73,6 @@ func (m *Map) Get(key interface{}) (value interface{}, found bool) {
 	return m.tree.Get(key)
 }
 
-// Returns the left-most element in the tree map (minimum).
-func (m *Map) Left() (key interface{}) {
-	return m.tree.Left()
-}
-
-// Returns the right-most element in the tree map (maximum).
-func (m *Map) Right() (key interface{}) {
-	return m.tree.Right()
-}
-
 // Remove the element from the map by key.
 // Key should adhere to the comparator's type assertion, otherwise method panics.
 func (m *Map) Remove(key interface{}) {
@@ -114,6 +104,24 @@ func (m *Map) Clear() {
 	m.tree.Clear()
 }
 
+// Returns the minimum key and its value from the tree map.
+// Returns nil, nil if map is empty.
+func (m *Map) Min() (key interface{}, value interface{}) {
+	if node := m.tree.Left(); node != nil {
+		return node.Key, node.Value
+	}
+	return nil, nil
+}
+
+// Returns the maximum key and its value from the tree map.
+// Returns nil, nil if map is empty.
+func (m *Map) Max() (key interface{}, value interface{}) {
+	if node := m.tree.Right(); node != nil {
+		return node.Key, node.Value
+	}
+	return nil, nil
+}
+
 func (m *Map) String() string {
 	str := "TreeMap\n"
 	str += m.tree.String()

maps/treemap/treemap_test.go

@@ -60,14 +60,14 @@ func TestTreeMap(t *testing.T) {
 		t.Errorf("Got %v expected %v", actualValue, expectedValue)
 	}
 
-	// test Left()
+	// test Min()
-	if actualValue, expectedValue := fmt.Sprintf("%d", m.Left()), "1"; actualValue != expectedValue {
+	if key, value := m.Min(); key != 1 || value != "a" {
-		t.Errorf("Got %v expected %v", actualValue, expectedValue)
+		t.Errorf("Got %v expected %v", key, 1)
 	}
 
-	// test Right()
+	// test Max()
-	if actualValue, expectedValue := fmt.Sprintf("%d", m.Right()), "7"; actualValue != expectedValue {
+	if key, value := m.Max(); key != 7 || value != "g" {
-		t.Errorf("Got %v expected %v", actualValue, expectedValue)
+		t.Errorf("Got %v expected %v", key, 7)
 	}
 
 	// key,expectedValue,expectedFound
@@ -168,6 +168,15 @@ func TestTreeMap(t *testing.T) {
 		t.Errorf("Got %v expected %v", actualValue, true)
 	}
 
+	// test Min()
+	if key, value := m.Min(); key != nil || value != nil {
+		t.Errorf("Got %v expected %v", key, nil)
+	}
+
+	// test Max()
+	if key, value := m.Max(); key != nil || value != nil {
+		t.Errorf("Got %v expected %v", key, nil)
+	}
 }
 
 func BenchmarkTreeMap(b *testing.B) {