public void KeysISortedPred()
{
ISorted <string> keys = dict.Keys;
String res;
Assert.IsTrue(keys.TryPredecessor("S", out res));
Assert.AreEqual("R", res);
Assert.IsTrue(keys.TryWeakPredecessor("R", out res));
Assert.AreEqual("R", res);
Assert.IsTrue(keys.TrySuccessor("S", out res));
Assert.AreEqual("T", res);
Assert.IsTrue(keys.TryWeakSuccessor("T", out res));
Assert.AreEqual("T", res);
Assert.IsFalse(keys.TryPredecessor("R", out res));
Assert.AreEqual(null, res);
Assert.IsFalse(keys.TryWeakPredecessor("P", out res));
Assert.AreEqual(null, res);
Assert.IsFalse(keys.TrySuccessor("T", out res));
Assert.AreEqual(null, res);
Assert.IsFalse(keys.TryWeakSuccessor("U", out res));
Assert.AreEqual(null, res);
Assert.AreEqual("R", keys.Predecessor("S"));
Assert.AreEqual("R", keys.WeakPredecessor("R"));
Assert.AreEqual("T", keys.Successor("S"));
Assert.AreEqual("T", keys.WeakSuccessor("T"));
}
/// <summary>
/// Find the entry in the dictionary whose key is the
/// weak predecessor of the specified key.
/// </summary>
/// <param name="key">The key</param>
/// <param name="res">The predecessor, if any</param>
/// <returns>True if key has a weak predecessor</returns>
public bool TryWeakPredecessor(K key, out KeyValuePair <K, V> res)
{
return(sortedpairs.TryWeakPredecessor(new KeyValuePair <K, V>(key), out res));
}
/// <summary>
/// Find the weak predecessor of item in the guarded sorted collection,
/// that is, the greatest item in the collection smaller than or equal to the item.
/// </summary>
/// <param name="item">The item to find the weak predecessor for.</param>
/// <param name="res">The weak predecessor, if any; otherwise the default value for T.</param>
/// <returns>True if item has a weak predecessor; otherwise false.</returns>
public bool TryWeakPredecessor(T item, out T res)
{
return(sorted.TryWeakPredecessor(item, out res));
}