小煜
ab91b120e6
- 添加Blender插件核心文件：__init__.py、ui.py、property.py、preference.py - 添加插件工具模块：g.py、loop.py、generate_loop.py、const.py、op.py - 添加翻译工具：utils/trans.py - 添加PuLP线性规划库及其依赖文件，包括CBC求解器二进制文件 - 添加.gitignore和VSCode配置文件
52 lines
1.5 KiB
Python
52 lines
1.5 KiB
Python
from pulp import *
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import random
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from itertools import product
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def _bin_packing_instance(bins, seed=0):
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packed_bins = [[] for _ in range(bins)]
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bin_size = bins * 100
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random.seed(seed)
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for i in range(len(packed_bins)):
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remaining_size = bin_size
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while remaining_size >= 1:
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item = random.randrange(1, remaining_size + 10)
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packed_bins[i].append(item)
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remaining_size -= item
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packed_bins[i][-1] += remaining_size
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all_items_with_bin = [(n, i) for i, l in enumerate(packed_bins) for n in l]
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random.shuffle(all_items_with_bin)
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items, packing = zip(*all_items_with_bin)
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return items, packing, bin_size
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def create_bin_packing_problem(bins, seed=0):
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items, packing, bin_size = _bin_packing_instance(bins=bins, seed=seed)
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prob = LpProblem("bin_packing", LpMinimize)
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bin_indices = [i for i in range(len(items))]
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item_indices = [i for i in range(len(items))]
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using_bin = LpVariable.dicts("y", bin_indices, cat=LpBinary)
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items_packed = LpVariable.dicts(
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"x", indices=product(item_indices, bin_indices), cat=LpBinary
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)
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prob += lpSum(using_bin), "objective"
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# pack every item
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for i in item_indices:
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prob += lpSum(items_packed[i, b] for b in bin_indices) == 1, f"pack_item_{i}"
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# no bin overfilled
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for b in bin_indices:
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expr = (
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lpSum([items[i] * items_packed[i, b] for i in item_indices])
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<= bin_size * using_bin[b]
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)
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prob += expr, f"respect_bin_size_{b}"
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return prob
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