Files
ortools-clone/examples/python/cover_rectangle_sat.py

94 lines
2.9 KiB
Python
Raw Normal View History

2018-12-23 18:16:16 +01:00
# Copyright 2010-2018 Google LLC
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
# Fill a 72x37 rectangle by a minimum number of non-overlapping squares.
from __future__ import print_function
from __future__ import division
from ortools.sat.python import cp_model
def CoverRectangle(num_squares):
size_x = 72
size_y = 37
model = cp_model.CpModel()
areas = []
sizes = []
x_intervals = []
y_intervals = []
sxs = []
sys = []
for i in range(num_squares):
size = model.NewIntVar(1, size_y, 'size_%i' % i)
sx = model.NewIntVar(0, size_x, 'sx_%i' % i)
ex = model.NewIntVar(0, size_x, 'ex_%i' % i)
sy = model.NewIntVar(0, size_y, 'sy_%i' % i)
ey = model.NewIntVar(0, size_y, 'ey_%i' % i)
i_x = model.NewIntervalVar(sx, size, ex, 'x_interval_%i' % i)
i_y = model.NewIntervalVar(sy, size, ey, 'y_interval_%i' % i)
area = model.NewIntVar(1, size_y * size_y, 'area_%i' % i)
model.AddProdEquality(area, [size, size])
areas.append(area)
x_intervals.append(i_x)
y_intervals.append(i_y)
sizes.append(size)
sxs.append(sx)
sys.append(sy)
model.AddNoOverlap2D(x_intervals, y_intervals)
model.AddCumulative(x_intervals, sizes, size_y)
model.AddCumulative(y_intervals, sizes, size_x)
model.Add(sum(areas) == size_x * size_y)
for i in range(num_squares - 1):
model.Add(sizes[i] <= sizes[i + 1])
# Creates a solver and solves.
solver = cp_model.CpSolver()
solver.parameters.num_search_workers = 4
status = solver.Solve(model)
print(solver.StatusName(status), solver.WallTime(), 'ms')
if (status == cp_model.FEASIBLE):
display = [[' ' for _ in range(size_x)] for _ in range(size_y)]
for i in range(num_squares):
x = solver.Value(sxs[i])
y = solver.Value(sys[i])
s = solver.Value(sizes[i])
c = format(i, ' 01x')
for j in range(s):
for k in range(s):
if display[y + j][x + k] != ' ':
print('ERROR between %s and %s' %
(display[y + j][x + k], c))
display[y + j][x + k] = c
for line in range(size_y):
print("".join(display[line]))
return status == cp_model.FEASIBLE
for i in range(15):
print('Trying with size =', i)
if CoverRectangle(i):
break