public void CanRemove()
{
var pq = new TestPriorityQueue <char>();
foreach (char c in "abcdefghijklmnopqrstuvwxyz")
{
pq.Add(c);
}
Assert.IsFalse(pq.Remove('$')); // no such item
Assert.AreEqual(26, pq.Count);
// Last item: easy to remove
Assert.IsTrue(pq.Remove('z'));
Assert.AreEqual(25, pq.Count);
Assert.AreEqual('a', pq.Top());
Assert.IsFalse(pq.Contains('z'));
// Remove a bottom row item:
Assert.IsTrue(pq.Remove('w'));
Assert.AreEqual(24, pq.Count);
Assert.AreEqual('a', pq.Top());
Assert.IsFalse(pq.Contains('w'));
// Remove an inner item:
Assert.IsTrue(pq.Remove('e'));
Assert.AreEqual(23, pq.Count);
Assert.AreEqual('a', pq.Top());
Assert.IsFalse(pq.Contains('e'));
// Remove the root item:
Assert.IsTrue(pq.Remove('a'));
Assert.AreEqual(22, pq.Count);
Assert.AreEqual('b', pq.Top());
Assert.IsFalse(pq.Contains('a'));
// Remove returns false if not found:
Assert.IsFalse(pq.Remove('z'));
Assert.IsFalse(pq.Remove('w'));
Assert.IsFalse(pq.Remove('e'));
Assert.IsFalse(pq.Remove('a'));
// Pop remaining items and verify order:
Assert.AreEqual('b', pq.Pop());
Assert.AreEqual('c', pq.Pop());
Assert.AreEqual('d', pq.Pop());
Assert.AreEqual('f', pq.Pop());
Assert.AreEqual('g', pq.Pop());
Assert.AreEqual('h', pq.Pop());
Assert.AreEqual('i', pq.Pop());
Assert.AreEqual('j', pq.Pop());
Assert.AreEqual('k', pq.Pop());
Assert.AreEqual('l', pq.Pop());
Assert.AreEqual('m', pq.Pop());
Assert.AreEqual('n', pq.Pop());
Assert.AreEqual('o', pq.Pop());
Assert.AreEqual('p', pq.Pop());
Assert.AreEqual('q', pq.Pop());
Assert.AreEqual('r', pq.Pop());
Assert.AreEqual('s', pq.Pop());
Assert.AreEqual('t', pq.Pop());
Assert.AreEqual('u', pq.Pop());
Assert.AreEqual('v', pq.Pop());
Assert.AreEqual('x', pq.Pop());
Assert.AreEqual('y', pq.Pop());
Assert.AreEqual(0, pq.Count);
}
