Question

I am implementing a generic PriorityQueue in C# as part of homework.
The items are stored in an array.

class PQueue<T> : IPQueue<T>
{
    T[] items;
    //..
}

How can I compare two items. I guess the type with which PQueue is instantiated has to implement IComparable/IComparer. If so, how can I compare two elements in items?

What is the elegant way to design this.

Answer 1

First, you need to tell C# that <T> implements IComparable<T>

class PQueue<T> : IPQueue<T> where T : IComparable<T> {
    T[] items;
    //..
}

Now you can compare individual items, like this:

var cmp = items[i].CompareTo(items[j]);
if (cmp < 0) {
    // items[i] is less than items[j]
} else if (cmp > 0) {
    // items[i] is greater than items[j]
} else {
    // Items are equal
}