Question

In C++, with priority queue I can write:

priority_queue<int, vector<int>, greater<int>> min_pq;
priority_queue<int, vector<int>, less<int>> max_pq;

I wonder is there an equivalent way to do it in C# container? I’m implementing a priority queue, where I need a way to specify this behavior when the user use its constructor. I could use a boolean flag, but it just doesn’t look right to me. Any idea?

public class PriorityQueue<T> where T : IComparable<T> {
     private List<T> data;

     /// <summary>
     /// 
     /// </summary>
     /// <param name="item"></param>
     public void Push(T item) {

     }

     /// <summary>
     /// 
     /// </summary>
     public void Pop() {

     } 
}

Answer 1

An idiomatic solution in C# is to pass an instance of IComparer<T> to the constructor of your generic class.

public class PriorityQueue<T> {
    private readonly IComparer<T> comparer;
    public PriorityQueue(IComparer<T> comp = null) {
        comparer = comp ?? Comparer<T>.Default;
    }
}