C# Priority Queue

pq.cs

using System;
using System.Collections.Generic;

// From http://visualstudiomagazine.com/articles/2012/11/01/priority-queues-with-c.aspx
public class PriorityQueue<T> where T : IComparable<T> {
	private List<T> data;

	public PriorityQueue() {
		this.data = new List<T>();
	}

	public void Enqueue(T item) {
		data.Add(item);
		int ci = data.Count - 1; // child index; start at end
		while (ci > 0) {
			int pi = (ci - 1) / 2; // parent index
			if (data[ci].CompareTo(data[pi]) >= 0)
				break; // child item is larger than (or equal) parent so we're done
			T tmp = data[ci];
			data[ci] = data[pi];
			data[pi] = tmp;
			ci = pi;
		}
	}

	public T Dequeue() {
		// assumes pq is not empty; up to calling code
		int li = data.Count - 1; // last index (before removal)
		T frontItem = data[0];   // fetch the front
		data[0] = data[li];
		data.RemoveAt(li);

		--li; // last index (after removal)
		int pi = 0; // parent index. start at front of pq
		while (true) {
			int ci = pi * 2 + 1; // left child index of parent
			if (ci > li)
				break;  // no children so done
			int rc = ci + 1;     // right child
			if (rc <= li && data[rc].CompareTo(data[ci]) < 0) // if there is a rc (ci + 1), and it is smaller than left child, use the rc instead
      ci = rc;
			if (data[pi].CompareTo(data[ci]) <= 0)
				break; // parent is smaller than (or equal to) smallest child so done
			T tmp = data[pi];
			data[pi] = data[ci];
			data[ci] = tmp; // swap parent and child
			pi = ci;
		}
		return frontItem;
	}

	public T Peek() {
		T frontItem = data[0];
		return frontItem;
	}

	public int Count() {
		return data.Count;
	}

	public override string ToString() {
		string s = "";
		for (int i = 0; i < data.Count; ++i)
			s += data[i].ToString() + " ";
		s += "count = " + data.Count;
		return s;
	}

	public bool IsConsistent() {
		// is the heap property true for all data?
		if (data.Count == 0)
			return true;
		int li = data.Count - 1; // last index
		for (int pi = 0; pi < data.Count; ++pi) { // each parent index
			int lci = 2 * pi + 1; // left child index
			int rci = 2 * pi + 2; // right child index

			if (lci <= li && data[pi].CompareTo(data[lci]) > 0)
				return false; // if lc exists and it's greater than parent then bad.
			if (rci <= li && data[pi].CompareTo(data[rci]) > 0)
				return false; // check the right child too.
		}
		return true; // passed all checks
	}
	// IsConsistent
}
 // PriorityQueue