void printTree(StringRedBlackTree tree, string indent, int node)
{
if (node == StringRedBlackTree.NULL)
{
System.Console.Error.WriteLine(indent + "NULL");
}
else
{
System.Console.Error.WriteLine(indent + "Node " + node + " color " +
(tree.isRed(node) ? "red" : "black"));
printTree(tree, indent + " ", tree.getLeft(node));
printTree(tree, indent + " ", tree.getRight(node));
}
}
/**
* Checks the red-black tree rules to make sure that we have correctly built
* a valid tree.
*
* Properties:
* 1. Red nodes must have black children
* 2. Each node must have the same black height on both sides.
*
* @param node The id of the root of the subtree to check for the red-black
* tree properties.
* @return The black-height of the subtree.
*/
private int checkSubtree(StringRedBlackTree tree, int node, ref int count)
{
if (node == StringRedBlackTree.NULL)
{
return(1);
}
count++;
bool is_red = tree.isRed(node);
int left = tree.getLeft(node);
int right = tree.getRight(node);
if (is_red)
{
if (tree.isRed(left))
{
printTree(tree, "", tree.Root);
throw new InvalidOperationException("Left node of " + node + " is " + left +
" and both are red.");
}
if (tree.isRed(right))
{
printTree(tree, "", tree.Root);
throw new InvalidOperationException("Right node of " + node + " is " +
right + " and both are red.");
}
}
int left_depth = checkSubtree(tree, left, ref count);
int right_depth = checkSubtree(tree, right, ref count);
if (left_depth != right_depth)
{
printTree(tree, "", tree.Root);
throw new InvalidOperationException("Lopsided tree at node " + node +
" with depths " + left_depth + " and " + right_depth);
}
if (is_red)
{
return(left_depth);
}
else
{
return(left_depth + 1);
}
}
void printTree(StringRedBlackTree tree, string indent, int node)
{
if (node == StringRedBlackTree.NULL)
{
System.Console.Error.WriteLine(indent + "NULL");
}
else
{
System.Console.Error.WriteLine(indent + "Node " + node + " color " +
(tree.isRed(node) ? "red" : "black"));
printTree(tree, indent + " ", tree.getLeft(node));
printTree(tree, indent + " ", tree.getRight(node));
}
}
/**
* Checks the red-black tree rules to make sure that we have correctly built
* a valid tree.
*
* Properties:
* 1. Red nodes must have black children
* 2. Each node must have the same black height on both sides.
*
* @param node The id of the root of the subtree to check for the red-black
* tree properties.
* @return The black-height of the subtree.
*/
private int checkSubtree(StringRedBlackTree tree, int node, ref int count)
{
if (node == StringRedBlackTree.NULL)
{
return 1;
}
count++;
bool is_red = tree.isRed(node);
int left = tree.getLeft(node);
int right = tree.getRight(node);
if (is_red)
{
if (tree.isRed(left))
{
printTree(tree, "", tree.Root);
throw new InvalidOperationException("Left node of " + node + " is " + left +
" and both are red.");
}
if (tree.isRed(right))
{
printTree(tree, "", tree.Root);
throw new InvalidOperationException("Right node of " + node + " is " +
right + " and both are red.");
}
}
int left_depth = checkSubtree(tree, left, ref count);
int right_depth = checkSubtree(tree, right, ref count);
if (left_depth != right_depth)
{
printTree(tree, "", tree.Root);
throw new InvalidOperationException("Lopsided tree at node " + node +
" with depths " + left_depth + " and " + right_depth);
}
if (is_red)
{
return left_depth;
}
else
{
return left_depth + 1;
}
}