One advantage that no one else has pointed out is that binary search tree allows you to do range searches efficiently. In order to illustrate my idea, I want to make an extreme case. Say you want to get all the elements whose keys are between 0 to 5000. And actually there is only one … Read more
I’ve asked Josh Bloch, and he informs me that it was a mistake. He used to think, long ago, that there was some value in it, but he since “saw the light”. Clearly JDK maintainers haven’t considered this to be worth backing out later.
I would recommend you to try Google SparseHash (or the C11 version Google SparseHash-c11) and see if it suits your needs. They have a memory efficient implementation as well as one optimized for speed. I did a benchmark a long time ago, it was the best hashtable implementation available in terms of speed (however with … Read more
I think you can use JSON.stringify: // after your each loop JSON.stringify(values);
Update Martin R writes: As of Swift 4.1, the compiler can synthesize Equatable and Hashable for types conformance automatically, if all members conform to Equatable/Hashable (SE0185). And as of Swift 4.2, a high-quality hash combiner is built-in into the Swift standard library (SE-0206). Therefore there is no need anymore to define your own hashing function, … Read more
Advantages of tries: The basics: Predictable O(k) lookup time where k is the size of the key Lookup can take less than k time if it’s not there Supports ordered traversal No need for a hash function Deletion is straightforward New operations: You can quickly look up prefixes of keys, enumerate all entries with a … Read more
Apart from the possibility that the values in your htable may be invalid pointers (i.e., neither NULL nor a pointer to a decent C string), you have a serious problem of encountering an infinite loop if it contains neither a NULL nor the string you’re looking for. For the immediate problem, try changing the code … Read more
java.util.HashMap is unordered; you can’t and shouldn’t assume anything beyond that. This class makes no guarantees as to the order of the map; in particular, it does not guarantee that the order will remain constant over time. java.util.LinkedHashMap uses insertion-order. This implementation differs from HashMap in that it maintains a doubly-linked list running through all … Read more
It’s impossible to know in advance how many collisions you will get with your hash function, as well as things like needing to resize. This can add an element of unpredictability to the performance of a hash table, making it not true O(1). However, virtually all hash table implementations offer O(1) on the vast, vast, … Read more
I think you are looking for the Dictionary object, found in the Microsoft Scripting Runtime library. (Add a reference to your project from the Tools…References menu in the VBE.) It pretty much works with any simple value that can fit in a variant (Keys can’t be arrays, and trying to make them objects doesn’t make … Read more