Data update

Task/AVL-tree/FreeBASIC/avl-tree-1.basic

@@ -0,0 +1,160 @@
+#define max(a, b) iif((a > b), a, b)
+
+Enum
+    _KEY
+    _RIGHT
+    _LEFT
+    _HEIGHT
+End Enum
+
+Dim Shared As Integer root = 0
+Dim Shared As Integer ramas = 5, indice = 0
+Dim Shared As Integer arbol(ramas, 4)
+
+Function height(current As Integer) As Integer
+    Return Iif(current = 0, 0, arbol(current, _HEIGHT))
+End Function
+
+Function Balance(current As Integer) As Integer
+    Return height(arbol(current, _LEFT)) - height(arbol(current, _RIGHT))
+End Function
+
+Function rotateRight(y As Integer) As Integer
+    Dim As Integer x, T2
+
+    x = arbol(y, _LEFT)
+    T2 = arbol(x, _RIGHT)
+    arbol(x, _RIGHT) = y
+    arbol(y, _LEFT) = T2
+    arbol(y, _HEIGHT) = max(height(arbol(y, _LEFT)), height(arbol(y, _RIGHT))) + 1
+    arbol(x, _HEIGHT) = max(height(arbol(x, _LEFT)), height(arbol(x, _RIGHT))) + 1
+    Return x
+End Function
+
+Function rotateLeft(x As Integer) As Integer
+    Dim As Integer y, T2
+
+    y = arbol(x, _RIGHT)
+    T2 = arbol(y, _LEFT)
+    arbol(y, _LEFT) = x
+    arbol(x, _RIGHT) = T2
+    arbol(x, _HEIGHT) = max(height(arbol(x, _LEFT)), height(arbol(x, _RIGHT))) + 1
+    arbol(y, _HEIGHT) = max(height(arbol(y, _LEFT)), height(arbol(y, _RIGHT))) + 1
+    Return y
+End Function
+
+Function insert(current As Integer, key As Integer) As Integer
+    Dim As Integer balanceo
+
+    If current = 0 Then
+        indice += 1
+        If indice > ramas Then
+            ramas += 5
+            Redim Preserve arbol(ramas, 4)
+        End If
+        arbol(indice, _KEY) = key
+        arbol(indice, _HEIGHT) = 1
+        Return indice
+    End If
+
+    If key < arbol(current, _KEY) Then
+        arbol(current, _LEFT) = insert(arbol(current, _LEFT), key)
+    Elseif key > arbol(current, _KEY) Then
+        arbol(current, _RIGHT) = insert(arbol(current, _RIGHT), key)
+    Else
+        Return current
+    End If
+
+    arbol(current, _HEIGHT) = max(height(arbol(current, _LEFT)), height(arbol(current, _RIGHT))) + 1
+    balanceo = Balance(current)
+
+    If balanceo > 1  And key < arbol(arbol(current, _LEFT), _KEY) Then Return rotateRight(current)
+    If balanceo < -1 And key > arbol(arbol(current, _RIGHT), _KEY) Then Return rotateLeft(current)
+    If balanceo > 1  And key > arbol(arbol(current, _LEFT), _KEY) Then
+        arbol(current, _LEFT) = rotateLeft(arbol(current, _LEFT))
+        Return rotateRight(current)
+    End If
+    If balanceo < -1 And key < arbol(arbol(current, _RIGHT), _KEY) Then
+        arbol(current, _RIGHT) = rotateRight(arbol(current, _RIGHT))
+        Return rotateLeft(current)
+    End If
+
+    Return current
+End Function
+
+Function minValueNode(current As Integer) As Integer
+    While arbol(current, _LEFT) '<> 0
+        current = arbol(current, _LEFT)
+    Wend
+    Return current
+End Function
+
+Function deleteNode(root As Integer, key As Integer) As Integer
+    Dim As Integer temp, balanceo
+    ' Find the node and delete it
+    If root = 0 Then Return root
+
+    If key < arbol(root, _KEY) Then
+        arbol(root, _LEFT) = deleteNode(arbol(root, _LEFT), key)
+    Elseif key > arbol(root, _KEY) Then
+        arbol(root, _RIGHT) = deleteNode(arbol(root, _RIGHT), key)
+    Else
+        If arbol(root, _LEFT) = 0 Or arbol(root, _RIGHT) = 0 Then
+            temp = max(arbol(root, _LEFT), arbol(root, _RIGHT))
+            If temp = 0 Then
+                temp = root
+                root = 0
+            Else
+                root = temp
+            End If
+        Else
+            temp = minValueNode(arbol(root, _RIGHT))
+            arbol(root, _KEY) = arbol(temp, _KEY)
+            arbol(root, _RIGHT) = deleteNode(arbol(root, _RIGHT), arbol(temp, _KEY))
+        End If
+    End If
+
+    If root = 0 Then Return root
+
+    ' Update the balance factor of each node and balance the tree
+    arbol(root, _HEIGHT) = 1 + max(height(arbol(root, _LEFT)), height(arbol(root, _RIGHT)))
+
+    balanceo = Balance(root)
+    If balanceo > 1 And Balance(arbol(root, _LEFT)) >= 0 Then Return rotateRight(root)
+    If balanceo > 1 And Balance(arbol(root, _LEFT)) < 0  Then
+        arbol(root, _LEFT) = rotateLeft(arbol(root, _LEFT))
+        Return rotateRight(root)
+    End If
+    If balanceo < -1 And Balance(arbol(root, _RIGHT)) <= 0 Then Return rotateLeft(root)
+    If balanceo < -1 And Balance(arbol(root, _RIGHT)) > 0  Then
+        arbol(root, _RIGHT) = rotateRight(arbol(root, _RIGHT))
+        Return rotateLeft(root)
+    End If
+
+    Return root
+End Function
+
+Sub preOrder(temp As Integer)
+    If temp <> 0 Then
+        Print arbol(temp, _KEY); arbol(temp, _HEIGHT); Balance(temp)
+        preOrder(arbol(temp, _LEFT))
+        preOrder(arbol(temp, _RIGHT))
+    End If
+End Sub
+
+root = insert(root, 2)
+root = insert(root, 1)
+root = insert(root, 7)
+root = insert(root, 4)
+root = insert(root, 5)
+root = insert(root, 3)
+root = insert(root, 8)
+
+preOrder(root)
+
+root = deleteNode(root, 3)
+
+Print !"\nAfter deletion: "
+preOrder(root)
+
+Sleep