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# 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.
# [START program]
"""Simple travelling salesman problem on a circuit board."""
# [START import]
from __future__ import print_function
import math
from ortools.constraint_solver import routing_enums_pb2
from ortools.constraint_solver import pywrapcp
# [END import]
# [START data_model]
def create_data_model():
"""Stores the data for the problem."""
data = {}
# Locations in block units
data['locations'] = [
(288, 149), (288, 129), (270, 133), (256, 141), (256, 157), (246, 157),
(236, 169), (228, 169), (228, 161), (220, 169), (212, 169), (204, 169),
(196, 169), (188, 169), (196, 161), (188, 145), (172, 145), (164, 145),
(156, 145), (148, 145), (140, 145), (148, 169), (164, 169), (172, 169),
(156, 169), (140, 169), (132, 169), (124, 169), (116, 161), (104, 153),
(104, 161), (104, 169), (90, 165), (80, 157), (64, 157), (64, 165),
(56, 169), (56, 161), (56, 153), (56, 145), (56, 137), (56, 129),
(56, 121), (40, 121), (40, 129), (40, 137), (40, 145), (40, 153),
(40, 161), (40, 169), (32, 169), (32, 161), (32, 153), (32, 145),
(32, 137), (32, 129), (32, 121), (32, 113), (40, 113), (56, 113),
(56, 105), (48, 99), (40, 99), (32, 97), (32, 89), (24, 89),
(16, 97), (16, 109), (8, 109), (8, 97), (8, 89), (8, 81),
(8, 73), (8, 65), (8, 57), (16, 57), (8, 49), (8, 41),
(24, 45), (32, 41), (32, 49), (32, 57), (32, 65), (32, 73),
(32, 81), (40, 83), (40, 73), (40, 63), (40, 51), (44, 43),
(44, 35), (44, 27), (32, 25), (24, 25), (16, 25), (16, 17),
(24, 17), (32, 17), (44, 11), (56, 9), (56, 17), (56, 25),
(56, 33), (56, 41), (64, 41), (72, 41), (72, 49), (56, 49),
(48, 51), (56, 57), (56, 65), (48, 63), (48, 73), (56, 73),
(56, 81), (48, 83), (56, 89), (56, 97), (104, 97), (104, 105),
(104, 113), (104, 121), (104, 129), (104, 137), (104, 145), (116, 145),
(124, 145), (132, 145), (132, 137), (140, 137), (148, 137), (156, 137),
(164, 137), (172, 125), (172, 117), (172, 109), (172, 101), (172, 93),
(172, 85), (180, 85), (180, 77), (180, 69), (180, 61), (180, 53),
(172, 53), (172, 61), (172, 69), (172, 77), (164, 81), (148, 85),
(124, 85), (124, 93), (124, 109), (124, 125), (124, 117), (124, 101),
(104, 89), (104, 81), (104, 73), (104, 65), (104, 49), (104, 41),
(104, 33), (104, 25), (104, 17), (92, 9), (80, 9), (72, 9),
(64, 21), (72, 25), (80, 25), (80, 25), (80, 41), (88, 49),
(104, 57), (124, 69), (124, 77), (132, 81), (140, 65), (132, 61),
(124, 61), (124, 53), (124, 45), (124, 37), (124, 29), (132, 21),
(124, 21), (120, 9), (128, 9), (136, 9), (148, 9), (162, 9),
(156, 25), (172, 21), (180, 21), (180, 29), (172, 29), (172, 37),
(172, 45), (180, 45), (180, 37), (188, 41), (196, 49), (204, 57),
(212, 65), (220, 73), (228, 69), (228, 77), (236, 77), (236, 69),
(236, 61), (228, 61), (228, 53), (236, 53), (236, 45), (228, 45),
(228, 37), (236, 37), (236, 29), (228, 29), (228, 21), (236, 21),
(252, 21), (260, 29), (260, 37), (260, 45), (260, 53), (260, 61),
(260, 69), (260, 77), (276, 77), (276, 69), (276, 61), (276, 53),
(284, 53), (284, 61), (284, 69), (284, 77), (284, 85), (284, 93),
(284, 101), (288, 109), (280, 109), (276, 101), (276, 93), (276, 85),
(268, 97), (260, 109), (252, 101), (260, 93), (260, 85), (236, 85),
(228, 85), (228, 93), (236, 93), (236, 101), (228, 101), (228, 109),
(228, 117), (228, 125), (220, 125), (212, 117), (204, 109), (196, 101),
(188, 93), (180, 93), (180, 101), (180, 109), (180, 117), (180, 125),
(196, 145), (204, 145), (212, 145), (220, 145), (228, 145), (236, 145),
(246, 141), (252, 125), (260, 129), (280, 133)
] # yapf: disable
data['num_vehicles'] = 1
data['depot'] = 0
return data
# [END data_model]
# [START distance_callback]
def compute_euclidean_distance_matrix(locations):
"""Creates callback to return distance between points."""
distances = {}
for from_counter, from_node in enumerate(locations):
distances[from_counter] = {}
for to_counter, to_node in enumerate(locations):
if from_counter == to_counter:
distances[from_counter][to_counter] = 0
else:
# Euclidean distance
distances[from_counter][to_counter] = (int(
math.hypot((from_node[0] - to_node[0]),
(from_node[1] - to_node[1]))))
return distances
# [END distance_callback]
# [START solution_printer]
def print_solution(manager, routing, solution):
"""Prints solution on console."""
print('Objective: {}'.format(solution.ObjectiveValue()))
index = routing.Start(0)
plan_output = 'Route:\n'
route_distance = 0
while not routing.IsEnd(index):
plan_output += ' {} ->'.format(manager.IndexToNode(index))
previous_index = index
index = solution.Value(routing.NextVar(index))
route_distance += routing.GetArcCostForVehicle(previous_index, index, 0)
plan_output += ' {}\n'.format(manager.IndexToNode(index))
print(plan_output)
plan_output += 'Objective: {}m\n'.format(route_distance)
# [END solution_printer]
"""Entry point of the program."""
# Instantiate the data problem.
# [START data]
data = create_data_model()
# [END data]
# Create the routing index manager.
# [START index_manager]
manager = pywrapcp.RoutingIndexManager(len(data['locations']),
data['num_vehicles'], data['depot'])
# [END index_manager]
# Create Routing Model.
# [START routing_model]
routing = pywrapcp.RoutingModel(manager)
# [END routing_model]
# [START transit_callback]
distance_matrix = compute_euclidean_distance_matrix(data['locations'])
def distance_callback(from_index, to_index):
"""Returns the distance between the two nodes."""
# Convert from routing variable Index to distance matrix NodeIndex.
from_node = manager.IndexToNode(from_index)
to_node = manager.IndexToNode(to_index)
return distance_matrix[from_node][to_node]
transit_callback_index = routing.RegisterTransitCallback(distance_callback)
# [END transit_callback]
# Define cost of each arc.
# [START arc_cost]
routing.SetArcCostEvaluatorOfAllVehicles(transit_callback_index)
# [END arc_cost]
# Setting first solution heuristic.
# [START parameters]
search_parameters = pywrapcp.DefaultRoutingSearchParameters()
search_parameters.first_solution_strategy = (
routing_enums_pb2.FirstSolutionStrategy.PATH_CHEAPEST_ARC)
# [END parameters]
# Solve the problem.
# [START solve]
solution = routing.SolveWithParameters(search_parameters)
# [END solve]
# Print solution on console.
# [START print_solution]
if solution:
print_solution(manager, routing, solution)
# [END print_solution]