3D-Projects/OfficeShelf/zuschnitt.py

import time


class LengthError(ValueError):
    pass


class Cut(object):

    def __init__(self, l):
        self.Length = l


class CutableRod(object):

    def __init__(self):
        self.Length = 6000
        self.CutThickness = 0
        self.Remainder = self.Length
        self.Cuts = []

    def addCut(self, cut):
        if not self.canAddCut(cut):
            raise LengthError("Cut.Length=%i, Remainder=%i" % (cut.Length, self.Remainder))
        self.Cuts.append(cut)
        self.Remainder -= cut.Length
        self.Remainder -= self.CutThickness

    def copy(self):
        new_rod = CutableRod()
        new_rod.Length = self.Length
        new_rod.CutThickness = self.CutThickness
        new_rod.Remainder = self.Remainder
        for c in self.Cuts:
            new_rod.Cuts.append(c)
        return new_rod

    def canAddCut(self, cut):
        return self.Remainder >= cut.Length

    def variety(self):
        """ Amount of different cut lengths
        """
        lengths = []
        for cut in self.Cuts:
            if cut.Length not in lengths:
                lengths.append(cut.Length)
        return len(lengths)


class CutSolution(object):

    def __init__(self):
        self.Rods = []

    def isBetterThan(self, other):
        if self.rods() != other.rods():
            return self.rods() < other.rods()
        elif self.remainder() != other.remainder():
            return self.remainder() < other.remainder()
        elif self.variety() != other.variety():
            return self.variety() < other.variety()
        else:
            return False

    def copy(self):
        new_solution = CutSolution()
        for r in self.Rods:
            new_solution.Rods.append(r.copy())
        return new_solution

    def variety(self):
        variety = 0
        for r in self.Rods:
            v = r.variety()
            if v > 1:
                variety += v
        return variety

    def rods(self):
        return len(self.Rods)

    def remainder(self):
        remainder = 0
        for r in self.Rods:
            remainder += r.Remainder
        return remainder

    def print(self, short=False):
        if not short:
            print("\nSolution")
            for idx_r in range(len(self.Rods)):
                r = self.Rods[idx_r]
                print("Rod ", idx_r, ": ", end="", sep="")
                for idx_c in range(len(r.Cuts)):
                    c = r.Cuts[idx_c]
                    print(c.Length, " ", end="", sep="")
                print("(-", r.Remainder, ")", sep="")

        print("Rods=", self.rods(), ", Remainder=", self.remainder(), ", Variety=", self.variety(), sep="")


class CutRequest(object):

    def __init__(self):
        self.Cuts = []
        self.CreatedSolutions = []


    def add(self, amount, length):
        for i in range(amount):
            c = Cut(length)
            self.Cuts.append(c)


    def _iterate(self, current_solution, remaining_cuts):
        if len(remaining_cuts) == 0:
            return current_solution

        best_solution = None

        tested_lengths = []
        for idx_try in range(len(remaining_cuts)):
            cut = remaining_cuts[idx_try]

            # avoid testing same length again
            if cut.Length in tested_lengths:
                continue
            tested_lengths.append(cut.Length)

            # create temporary solution for trial
            trysol = CutSolution() if current_solution is None else current_solution.copy()

            # add cut to temporary solution
            if len(trysol.Rods) == 0 or not trysol.Rods[-1].canAddCut(cut):
                trysol.Rods.append(CutableRod())
            trysol.Rods[-1].addCut(cut)

            # create list of remaining other cuts
            remaining_cuts_without_try = []
            for idx_other in range(len(remaining_cuts)):
                if idx_other != idx_try:
                    cut_other = remaining_cuts[idx_other]
                    remaining_cuts_without_try.append(cut_other)

            # solve for tried remaining cuts
            trysol = self._iterate(trysol, remaining_cuts_without_try)

            # keep best solution
            if best_solution is None or trysol.isBetterThan(best_solution):
                best_solution = trysol
                if current_solution is None:
                    print("Better Solution: ", end="")
                    best_solution.print(True)

        return best_solution


    def arrangeCuts(self):
        time_start = time.time()
        solution = self._iterate(None, self.Cuts)
        solution.print()
        time_stop = time.time()
        print("duration: %0.1f" % (time_stop - time_start))


if __name__ == "__main__":

    cr = CutRequest()
    cr.add(8, 660);
    cr.add(16, 620);
    cr.add(1, 905);
    cr.add(2, 442);
    cr.add(2, 848);
    cr.add(4, 414);
    cr.arrangeCuts()