/*
* To use BKTree:
* 1. Create a class dervied from BKTreeNode
* 2. Add a member variable of your data to be sorted / retrieved
* 3. Override the calculateDistance method to calculate the distance metric
* between two nodes for the data to be sorted / retrieved.
* 4. Instantiate a BKTree with the type name of the class created in (1).
*/
static void Main(string[] args)
{
/*
* NOTE: More comprehensive examples of BK-Tree methods in unit tests
*/
// Exercise static distance metric methods -- just because
Console.WriteLine(
DistanceMetric.calculateHammingDistance(
new byte[] { 0xEF, 0x35, 0x20 },
new byte[] { 0xAD, 0x13, 0x87 }));
Console.WriteLine(
DistanceMetric.calculateLeeDistance(
new int[] { 196, 105, 48 },
new int[] { 201, 12, 51 }));
Console.WriteLine(
DistanceMetric.calculateLevenshteinDistance(
"kitten",
"sitting"));
// Create BKTree with derived node class from top of file
BKTree <ExampleNodeRecord> tree = new BKTree <ExampleNodeRecord>();
// Add some nodes
tree.add(new ExampleNodeRecord(1, new int[] { 100, 200, 300 }));
tree.add(new ExampleNodeRecord(2, new int[] { 110, 210, 310 }));
tree.add(new ExampleNodeRecord(3, new int[] { 120, 220, 320 }));
tree.add(new ExampleNodeRecord(4, new int[] { 130, 230, 330 }));
tree.add(new ExampleNodeRecord(5, new int[] { 140, 240, 340 }));
// Get best node from our tree with best distance
Dictionary <ExampleNodeRecord, Int32> results =
tree.findBestNodeWithDistance(
new ExampleNodeRecord(new int[] { 103, 215, 303 }));
// Get best nodes below threshold
results = tree.query(
new ExampleNodeRecord(new int[] { 103, 215, 303 }),
10); // arbitrary threshold
// Dictionaries don't print well; so invent your own handy print routine
}
} // String of symbols
// The only required method of abstract class BKTreeNode
override protected int calculateDistance(BKTreeNode node)
{
return(DistanceMetric.calculateLeeDistance(
this.Data,
((ExampleNodeRecord)node).Data));
}