/// <summary>
/// Tries to parse the first line <paramref name="text"/>.
/// </summary>
/// <param name="text"></param>
/// <param name="minionCount"></param>
/// <returns></returns>
private bool TryParseFirst(string text, out int minionCount)
{
var parts = PrepareText(text).Split(' ');
minionCount = 0;
if (parts.Length != 3)
throw new ArgumentException(string.Format("Input line 1 must contain N X Y: {{{0}}}", text), "text");
minionCount = int.Parse(parts[0]);
Spell = new ChainLightningSpell(parts[1], parts[2]);
if (minionCount > 10)
throw new ArgumentException(string.Format("Input line 1 must not specify more than 10 minions: {{{0}}}", text), "text");
Lines.Add(text);
return true;
}
/// <summary>
/// Casts the <paramref name="spell"/> on a group of <paramref name="minions"/>.
/// </summary>
/// <param name="spell"></param>
/// <param name="minions"></param>
/// <returns>The number of minions actually struck.</returns>
public int Cast(ChainLightningSpell spell, params Minion[] minions)
{
/* Will brute force compare them like this for now. Really, this sounds like a
* Constraint Satisfaction Problem, close neighbor to the Knapsack problem:
* i.e. fill knapsack with items within a budget. */
Minion target;
do
{
// This is the best filtering / sorting that we can do.
var remaining
= (from m in minions
orderby m.Health descending
where !m.HasBeenStruck
select m).ToArray();
// All done.
if (!remaining.Any()) break;
// Hold onto the last one in the event we cannot eliminate any of the minions.
var last = remaining.Last();
while (remaining.Any() && remaining.First().Health > spell.Damage)
remaining = remaining.Skip(1).ToArray();
// Target the first remaining one or the last one.
target = remaining.FirstOrDefault() ?? last;
// Keep going while we can hit a target.
} while (spell.TryHit(target));
return minions.Count(m => m.IsDead);
}