private static void TestTreeInvariants(string[] testValues)
{
var tree = BKTree.Create(testValues);
foreach (var value in testValues)
{
// With a threshold of 0, we should only find exactly the item we're searching for.
Assert.Single(tree.Find(value, threshold: 0), value.ToLower());
}
foreach (var value in testValues)
{
// With a threshold of 1, we should always at least find the item we're looking for.
// But we may also find additional items along with it.
var items = tree.Find(value, threshold: 1);
Assert.Contains(value.ToLower(), items);
// We better not be finding all items.
Assert.NotEqual(testValues.Length, items.Count);
}
foreach (var value in testValues)
{
// If we delete each individual character in each search string, we should still
// find the value in the tree.
for (var i = 0; i < value.Length; i++)
{
var items = tree.Find(Delete(value, i), threshold: null);
Assert.Contains(value.ToLower(), items);
// We better not be finding all items.
Assert.NotEqual(testValues.Length, items.Count);
}
}
foreach (var value in testValues)
{
// If we add a random character at any location in a string, we should still
// be able to find it.
for (var i = 0; i <= value.Length; i++)
{
var items = tree.Find(Insert(value, i, 'Z'), threshold: null);
Assert.Contains(value.ToLower(), items);
// We better not be finding all items.
Assert.NotEqual(testValues.Length, items.Count);
}
}
foreach (var value in testValues)
{
// If we transpose any characters in a string, we should still
// be able to find it.
for (var i = 0; i < value.Length - 1; i++)
{
var items = tree.Find(Transpose(value, i), threshold: null);
Assert.Contains(value.ToLower(), items);
}
}
}
public void SimpleTests()
{
string[] testValues =
{
"cook",
"book",
"books",
"cake",
"what",
"water",
"Cape",
"Boon",
"Cook",
"Cart"
};
var tree = BKTree.Create(testValues);
var results1 = tree.Find("wat", threshold: 1);
Assert.Single(results1, "what");
var results2 = tree.Find("wat", threshold: 2);
Assert.True(results2.SetEquals(Expected("cart", "what", "water")));
var results3 = tree.Find("caqe", threshold: 1);
Assert.True(results3.SetEquals(Expected("cake", "cape")));
}
public void Test2()
{
string[] testValues = { "Leeds", "York", "Bristol", "Leicester", "Hull", "Durham" };
var tree = BKTree.Create(testValues);
var results = tree.Find("hill", threshold: null);
Assert.True(results.SetEquals(Expected("hull")));
results = tree.Find("liecester", threshold: null);
Assert.True(results.SetEquals(Expected("leicester")));
results = tree.Find("leicestre", threshold: null);
Assert.True(results.SetEquals(Expected("leicester")));
results = tree.Find("lecester", threshold: null);
Assert.True(results.SetEquals(Expected("leicester")));
}