帮我写一个使用蚁群贪心算法的人与包裹拼车系统
时间: 2023-06-17 11:07:29 浏览: 48
好的,下面是一个简单的人与包裹拼车系统实现,使用蚁群贪心算法。
首先,我们需要定义一些基本的数据结构和变量:
- 人员列表:包括每个人的起始位置和目的地位置
- 包裹列表:包括每个包裹的起始位置和目的地位置
- 车辆列表:包括每个车辆的容量和当前载重
- 路线列表:包括每个车辆的行驶路线
- 蚂蚁数量:表示蚁群中蚂蚁的数量
- 蚁群参数:包括信息素挥发速率、信息素增加速率、启发式因子等
接下来,我们可以按照以下步骤实现算法:
1. 初始化信息素矩阵,每辆车的信息素初始值都为1。
2. 按照启发式函数计算每个人员和包裹的优先级。
3. 初始化蚁群,每只蚂蚁都从某一个人员或包裹出发。
4. 每只蚂蚁按照概率选择下一个要走的人员或包裹,并更新当前的载重和路线。
5. 每只蚂蚁完成一轮后,更新信息素矩阵。
6. 重复步骤4-5多次,直到蚁群收敛。
7. 输出每辆车的路线和载重。
下面是一个简单的 Python 实现:
```python
import random
# 定义基本数据结构和变量
persons = [(0, 5), (1, 3), (2, 4), (3, 2), (4, 1)]
packages = [(0, 2), (1, 4), (2, 5), (3, 1), (4, 3)]
vehicles = [{'capacity': 5, 'load': 0, 'route': []},
{'capacity': 5, 'load': 0, 'route': []}]
pheromone = [[1 for _ in range(len(persons) + len(packages))] for _ in range(len(vehicles))]
ants = 10
evaporation = 0.1
alpha = 1
beta = 2
# 启发式函数,计算每个人员或包裹的优先级
def heuristic(person_or_package, vehicle):
if person_or_package in vehicle['route']:
return 0
s = abs(vehicle['route'][-1][1] - person_or_package[0])
t = abs(person_or_package[1] - person_or_package[0])
return t / (s + 0.1)
# 计算每个人员或包裹的优先级
person_priorities = [heuristic(person, vehicles[0]) for person in persons]
package_priorities = [heuristic(package, vehicles[0]) for package in packages]
# 蚁群贪心算法
for iteration in range(50):
for ant in range(ants):
# 每只蚂蚁从某一个人员或包裹出发
if random.random() < 0.5:
current = random.choice(persons)
else:
current = random.choice(packages)
vehicle = random.choice(vehicles)
route = [current]
load = 0
# 蚂蚁按照概率选择下一个要走的人员或包裹,并更新当前的载重和路线
while len(route) < len(persons) + len(packages):
if current in persons:
priorities = person_priorities
else:
priorities = package_priorities
probabilities = [pheromone[vehicles.index(vehicle)][i] ** alpha * priorities[i] ** beta for i in range(len(persons) + len(packages)) if (i not in route) and (priorities[i] > 0)]
if not probabilities:
break
total = sum(probabilities)
probabilities = [p / total for p in probabilities]
next = random.choices(range(len(probabilities)), probabilities)[0]
if next < len(persons) and load + 1 <= vehicle['capacity']:
current = persons[next]
load += 1
elif next >= len(persons) and load + 1 <= vehicle['capacity']:
current = packages[next - len(persons)]
load += 1
else:
break
route.append(current)
# 更新当前车辆的载重和路线
vehicle['load'] += load
vehicle['route'] = route
# 更新信息素矩阵
for i in range(len(route) - 1):
if route[i] in persons:
j = persons.index(route[i])
else:
j = packages.index(route[i])
j += len(persons)
if route[i + 1] in persons:
k = persons.index(route[i + 1])
else:
k = packages.index(route[i + 1])
k += len(persons)
pheromone[vehicles.index(vehicle)][j] *= (1 - evaporation)
pheromone[vehicles.index(vehicle)][j] += evaporation / (len(route) - 1)
# 输出每辆车的路线和载重
for i, vehicle in enumerate(vehicles):
print(f"Vehicle {i}: {vehicle['route']}, load = {vehicle['load']}")
```