In this chapter, you will look at certain data structures and algorithms that are not available for you in the FCL through Version 3.5. Examples are provided for algorithms such as hash-code creation and string balancing. The FCL does not support every data structure you might need, so this chapter provides solutions for priority, binary and n-ary trees, and a multimap, as well as many other things.
You have created a class or structure that will be used as a key in a
Dictionary<T,U>. You need to overload the
GetHashCode method in order to return a good distribution of hash values (the Discussion section defines a good distribution of hash values). You also need to choose the best hash-code algorithm to use in the
GetHashCode method of your object.
The following procedures implement hash-code algorithms and can be used to override the
GetHashCode method. Included in the discussion of each method are the pros and cons of using it, as well as why you would want to use one instead of another.
In addition, it is desirable, for performance reasons, to use the return value of the
GetHashCode method to determine whether the data contained within two objects is equal. Calling
GetHashCode to return a hash value of two objects and comparing their hash values can be faster than calling the default implementation of
Equals on the
Object type, which individually tests ...