public static void Solve(Box[] boxes)
{
Stopwatch sw = Stopwatch.StartNew();
Truck[] trucks = new Truck[100];
for (int i = 0; i < trucks.Length; i++)
{
trucks[i] = new Truck()
{
Id = i,
}
}
;
double minTargetWeight = boxes.Sum(b => (double)b.Weight) / trucks.Length;
TargetWeight targetWeight = new TargetWeight()
{
Min = (int)Math.Floor(minTargetWeight),
Max = (int)Math.Ceiling(minTargetWeight),
};
foreach (Box b in boxes.OrderBy(b => - b.Weight))
{
Truck truck = null;
int truckBalance = int.MaxValue;
foreach (Truck t in trucks)
{
int balance = t.Weight;
if (balance < truckBalance)
{
truck = t;
truckBalance = balance;
}
}
truck.AddBox(b);
}
int bestScore = int.MaxValue;
Truck[] solution = null;
int ComplexOptimizationMaxMoves = boxes.Length < 1000 ? 1500 : 250;
#if LOCAL
double lastPrint = 0;
#endif
while (sw.Elapsed.TotalSeconds < MaxExecutionTimeSeconds && bestScore > targetWeight.Max - targetWeight.Min)
{
// Fix volume problems
foreach (Truck truck1 in trucks.OrderBy(t => - t.Volume).ToArray())
{
while (truck1.Volume > Truck.MaxVolume)
{
Box box1 = null;
Box box2 = null;
Truck truck2 = null;
int bestBalance = int.MaxValue;
foreach (Truck t2 in trucks)
{
if (truck1 != t2 && t2.Volume < Truck.MaxVolume)
{
foreach (Box b1 in truck1.Boxes)
{
foreach (Box b2 in t2.Boxes)
{
if (b1.Volume > b2.Volume && t2.Volume + b1.Volume - b2.Volume < Truck.MaxVolume)
{
int t1weight = truck1.Weight - b1.Weight + b2.Weight;
int t2weight = t2.Weight - b2.Weight + b1.Weight;
int balance = (targetWeight.Distance(t1weight) + targetWeight.Distance(t2weight)) - (targetWeight.Distance(truck1.Weight) + targetWeight.Distance(t2.Weight));
if (balance < bestBalance)
{
box1 = b1;
box2 = b2;
truck2 = t2;
bestBalance = balance;
}
}
}
}
}
}
if (box1 == null)
{
break;
}
truck1.RemoveBox(box1);
truck2.RemoveBox(box2);
truck1.AddBox(box2);
truck2.AddBox(box1);
}
}
// Complex optimization
ComplexOptimizationMaxMoves *= 2;
foreach (Truck t in trucks)
{
t.UpdateMoves(ComplexOptimizationMaxMoves);
}
for (int skip = 0; skip < trucks.Length && sw.Elapsed.TotalSeconds < MaxExecutionTimeSeconds;)
{
int score = trucks.Max(t => t.Weight) - trucks.Min(t => t.Weight);
if (score < bestScore && trucks.Max(t => t.Volume) < Truck.MaxVolume)
{
bestScore = score;
solution = boxes.Select(b => b.Truck).ToArray();
}
#if LOCAL
if (sw.Elapsed.TotalSeconds - lastPrint > 0.02)
{
Console.Write($"{bestScore} {sw.Elapsed.TotalSeconds}s {score} \r");
lastPrint = sw.Elapsed.TotalSeconds;
}
#endif
Truck[] fats = trucks.OrderBy(t => - targetWeight.Distance(t.Weight)).ThenBy(t => t.Id).Skip(skip).ToArray();
Truck truck1 = fats[0];
if (targetWeight.Distance(truck1.Weight) == 0)
{
break;
}
int t1balance = targetWeight.Distance(truck1.Weight);
ComplexMove move1 = null;
ComplexMove move2 = null;
Truck truck2 = null;
int newWeightBalance = t1balance;
foreach (Truck t2 in fats)
{
if (truck1 != t2)
{
int t2balance = targetWeight.Distance(t2.Weight);
int previousWeightBalance = t1balance + t2balance;
if (sw.Elapsed.TotalSeconds >= MaxExecutionTimeSeconds)
{
break;
}
foreach (ComplexMove m1 in truck1.Moves)
{
int minM2Volume = (t2.Volume + m1.Volume) - Truck.MaxVolume;
int maxM2Volume = Truck.MaxVolume - (truck1.Volume - m1.Volume);
int start = minM2Volume < t2.Moves[0].Volume ? 0 : LowerBound(t2.Moves, minM2Volume);
int end = maxM2Volume > t2.Moves[t2.Moves.Length - 1].Volume ? t2.Moves.Length : UpperBound(t2.Moves, maxM2Volume);
int t1weight = truck1.Weight - m1.Weight;
int t2weight = t2.Weight + m1.Weight;
for (int i = start; i < end; i++)
{
ComplexMove m2 = t2.Moves[i];
int t1w = t1weight + m2.Weight;
int weightBalance = targetWeight.Distance(t1w);
if (weightBalance >= newWeightBalance)
{
continue;
}
int t2w = t2weight - m2.Weight;
int balance = targetWeight.Distance(t2w) - t1balance;
if (balance >= 0)
{
continue;
}
{
move1 = m1;
move2 = m2;
truck2 = t2;
newWeightBalance = weightBalance;
}
}
}
}
}
if (truck2 == null)
{
skip++;
continue;
}
skip = 0;
foreach (Box b in move1.Boxes)
{
truck1.RemoveBox(b);
}
foreach (Box b in move2.Boxes)
{
truck2.RemoveBox(b);
}
foreach (Box b in move2.Boxes)
{
truck1.AddBox(b);
}
foreach (Box b in move1.Boxes)
{
truck2.AddBox(b);
}
truck1.UpdateMoves(ComplexOptimizationMaxMoves);
truck2.UpdateMoves(ComplexOptimizationMaxMoves);
}
#if LOCAL
//foreach (Truck t in trucks.OrderBy(t => targetWeight.Distance(t.Weight)).ToArray())
// Console.WriteLine($"{t.Id}: {targetWeight.Distance(t.Weight)}[{t.Boxes.Count}] {t.Weight / (double)Box.FixedPoint} {t.Volume / (double)Box.FixedPoint}");
#endif
// Randomize a bit
Truck[] ttt = trucks.Where(t => targetWeight.Distance(t.Weight) > 0).OrderBy(t => targetWeight.Distance(t.Weight)).ToArray();
bool[] touched = new bool[ttt.Length];
for (int i = 0; i < ttt.Length / 2 && sw.Elapsed.TotalSeconds < MaxExecutionTimeSeconds; i++)
{
if (!touched[i])
{
Truck t1 = ttt[i];
Truck truck1 = t1;
Truck truck2 = null;
int bestj = -1;
ComplexMove move1 = null;
ComplexMove move2 = null;
int bestDistance = int.MaxValue;
for (int j = 0; j < ttt.Length; j++)
{
if (i != j)
{
Truck t2 = ttt[j];
foreach (ComplexMove m1 in t1.Moves)
{
if (m1.Boxes.Length != t1.Boxes.Count)
{
int minM2Volume = (t2.Volume + m1.Volume) - Truck.MaxVolume;
int maxM2Volume = Truck.MaxVolume - (truck1.Volume - m1.Volume);
int start = minM2Volume < t2.Moves[0].Volume ? 0 : LowerBound(t2.Moves, minM2Volume);
int end = maxM2Volume > t2.Moves[t2.Moves.Length - 1].Volume ? t2.Moves.Length : UpperBound(t2.Moves, maxM2Volume);
for (int m2i = start; m2i < end; m2i++)
{
ComplexMove m2 = t2.Moves[m2i];
int distance = Math.Abs(m1.Weight - m2.Weight);
if (distance < bestDistance ||
(distance == bestDistance && m1.Boxes.Length + m2.Boxes.Length > move1.Boxes.Length + move2.Boxes.Length))
{
move1 = m1;
move2 = m2;
truck2 = t2;
bestDistance = distance;
bestj = j;
}
}
}
}
}
}
if (bestj == -1)
{
continue;
}
touched[i] = true;
touched[bestj] = true;
foreach (Box b in move1.Boxes)
{
truck1.RemoveBox(b);
}
foreach (Box b in move2.Boxes)
{
truck2.RemoveBox(b);
}
foreach (Box b in move2.Boxes)
{
truck1.AddBox(b);
}
foreach (Box b in move1.Boxes)
{
truck2.AddBox(b);
}
truck1.UpdateMoves(ComplexOptimizationMaxMoves);
truck2.UpdateMoves(ComplexOptimizationMaxMoves);
}
}
}
for (int i = 0; i < solution.Length; i++)
{
boxes[i].Truck = solution[i];
}
#if !LOCAL
Console.Error.WriteLine($"Time: {sw.Elapsed.TotalSeconds}s");
#endif
}