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Add SearchForAllSolution in sat cp_model.py API; add code to export model from the steel_mill_slab_sat code

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Laurent Perron
2017-11-05 10:31:52 +01:00
parent a4716f97f5
commit bdd72fe1b1
2 changed files with 37 additions and 10 deletions
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40
examples/python/steel_mill_slab_sat.py
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@@ -14,6 +14,9 @@ parser.add_argument('--break_symmetries', default = True, type = bool,
parser.add_argument(
'--solver', default = "mip_column",
help = 'Method used to solve: sat, sat_table, sat_column, mip_column.')
parser.add_argument('--output_proto', default = "",
help = 'Output file to write the cp_model proto to.')
def BuildProblem(problem_id):
@@ -284,7 +287,7 @@ class SolutionPrinterWithObjective(cp_model.CpSolverSolutionCallback):
self.__solution_count += 1
def SteelMillSlab(problem, break_symmetries):
def SteelMillSlab(problem, break_symmetries, output_proto):
"""Solves the Steel Mill Slab Problem."""
### Load problem.
(num_slabs, capacities, num_colors, orders) = BuildProblem(problem)
@@ -468,14 +471,22 @@ def CollectValidSlabs(capacities, colors, widths, loss_array, all_colors):
loss = model.NewIntVar(0, max(loss_array), 'loss')
model.AddElement(load, loss_array, loss)
print('Model created')
# Output model proto to file.
if output_proto:
f = open(output_proto, 'w')
f.write(str(model.ModelProto()))
f.close()
### Solve model and collect columns.
solver = cp_model.CpSolver()
collector = AllSolutionsCollector(assign + [loss, load])
solver.SolveWithSolutionObserver(model, collector)
solver.SearchForAllSolutions(model, collector)
return collector.AllSolutions()
def SteelMillSlabWithValidSlabs(problem, break_symmetries):
def SteelMillSlabWithValidSlabs(problem, break_symmetries, output_proto):
"""Solves the Steel Mill Slab Problem."""
### Load problem.
(num_slabs, capacities, num_colors, orders) = BuildProblem(problem)
@@ -589,9 +600,11 @@ def SteelMillSlabWithValidSlabs(problem, break_symmetries):
print('Model created')
f = open('/tmp/steel.pbtxt', 'w')
f.write(str(model.ModelProto()))
f.close()
# Output model proto to file.
if output_proto:
f = open(output_proto, 'w')
f.write(str(model.ModelProto()))
f.close()
### Solve model.
solver = cp_model.CpSolver()
@@ -606,7 +619,7 @@ def SteelMillSlabWithValidSlabs(problem, break_symmetries):
print('No solution')
def SteelMillSlabWithColumnGeneration(problem):
def SteelMillSlabWithColumnGeneration(problem, output_proto):
"""Solves the Steel Mill Slab Problem."""
### Load problem.
(num_slabs, capacities, num_colors, orders) = BuildProblem(problem)
@@ -661,6 +674,12 @@ def SteelMillSlabWithColumnGeneration(problem):
print('Model created')
# Output model proto to file.
if output_proto:
f = open(output_proto, 'w')
f.write(str(model.ModelProto()))
f.close()
### Solve model.
solver = cp_model.CpSolver()
solution_printer = SolutionPrinterWithObjective()
@@ -741,11 +760,12 @@ def SteelMillSlabWithMipColumnGeneration(problem):
def main(args):
if args.solver == 'sat':
SteelMillSlab(args.problem, args.break_symmetries)
SteelMillSlab(args.problem, args.break_symmetries, args.output_proto)
elif args.solver == 'sat_table':
SteelMillSlabWithValidSlabs(args.problem, args.break_symmetries)
SteelMillSlabWithValidSlabs(args.problem, args.break_symmetries,
args.output_proto)
elif args.solver == 'sat_column':
SteelMillSlabWithColumnGeneration(args.problem)
SteelMillSlabWithColumnGeneration(args.problem, args.output_proto)
else: # 'mip_column'
SteelMillSlabWithMipColumnGeneration(args.problem)