问题描述
我复制了一个 code example，它本身可以正常工作，并且在我的版本中也可以正常工作。问题是在向用户询问员工人数、班次和计划天数后，程序不会显示求解器的结果。它将单独对示例代码执行此操作，但不会使用我编写的用于控制它的代码。如果有人可以看看这个以了解原因，我们将不胜感激。
C#-8解决方法
过了某个时间点，最好尝试一种更简洁的方法，而不是查明当前错误的确切位置。这里有一个更好的方法来组织你正在做的事情，它似乎工作正常。
首先，复制自 example 的代码，“nurses”替换为“employees”，静态分配更改为用户输入，正如您所做的那样。我还将 main 重命名为 schedule_employees。
from ortools.sat.python import cp_model
class EmpsPartialSolutionPrinter(cp_model.CpSolverSolutionCallback):
"""Print intermediate solutions."""
def __init__(self,shifts,num_employees,num_days,num_shifts,sols):
cp_model.CpSolverSolutionCallback.__init__(self)
self._shifts = shifts
self._num_employees = num_employees
self._num_days = num_days
self._num_shifts = num_shifts
self._solutions = set(sols)
self._solution_count = 0
def on_solution_callback(self):
if self._solution_count in self._solutions:
print('Solution %i' % self._solution_count)
for d in range(self._num_days):
print('Day %i' % d)
for n in range(self._num_employees):
is_working = False
for s in range(self._num_shifts):
if self.Value(self._shifts[(n,d,s)]):
is_working = True
print(' Nurse %i works shift %i' % (n,s))
if not is_working:
print(' Nurse {} does not work'.format(n))
print()
self._solution_count += 1
def solution_count(self):
return self._solution_count
def schedule_employees():
# Data.
num_employees = int(input("How many employees are you scheduling? "))
num_days = int(input("How many days are you scheduling for? "))
num_shifts = int(input("How many shifts are you scheduling for each "
f"employees for {num_days} days? "))
all_employees = range(num_employees)
all_shifts = range(num_shifts)
all_days = range(num_days)
# Creates the model.
model = cp_model.CpModel()
# Creates shift variables.
# shifts[(n,s)]: nurse 'n' works shift 's' on day 'd'.
shifts = {}
for n in all_employees:
for d in all_days:
for s in all_shifts:
shifts[(n,s)] = model.NewBoolVar('shift_n%id%is%i' % (n,s))
# Each shift is assigned to exactly one nurse in the schedule period.
for d in all_days:
for s in all_shifts:
model.Add(sum(shifts[(n,s)] for n in all_employees) == 1)
# Each nurse works at most one shift per day.
for n in all_employees:
for d in all_days:
model.Add(sum(shifts[(n,s)] for s in all_shifts) <= 1)
# Try to distribute the shifts evenly,so that each nurse works
# min_shifts_per_nurse shifts. If this is not possible,because the total
# number of shifts is not divisible by the number of employees,some employees will
# be assigned one more shift.
min_shifts_per_nurse = (num_shifts * num_days) // num_employees
if num_shifts * num_days % num_employees == 0:
max_shifts_per_nurse = min_shifts_per_nurse
else:
max_shifts_per_nurse = min_shifts_per_nurse + 1
for n in all_employees:
num_shifts_worked = 0
for d in all_days:
for s in all_shifts:
num_shifts_worked += shifts[(n,s)]
model.Add(min_shifts_per_nurse <= num_shifts_worked)
model.Add(num_shifts_worked <= max_shifts_per_nurse)
# Creates the solver and solve.
solver = cp_model.CpSolver()
solver.parameters.linearization_level = 0
# Display the first five solutions.
a_few_solutions = range(5)
solution_printer = EmpsPartialSolutionPrinter(shifts,a_few_solutions)
solver.SearchForAllSolutions(model,solution_printer)
这或多或少是您需要添加/更改的全部内容。顶级入口点——基本上，你希望在执行脚本时首先发生的事情——进入 __name__ == '__main__' 检查，就像示例所做的那样。当然，不同之处在于我们在调用以前简单的 main 方法之前执行了一些检查。
if __name__ == '__main__':
valid_roles = ['supervisor','employee']
role = input('Are you an employee or supervisor? ')
while role not in valid_roles:
print('not a valid response')
role = input('Are you an employee or supervisor? ')
task = input('I want to: ')
if role == 'supervisor' and task == 'schedule employees':
schedule_employees()
如果您添加到此程序并且这些检查变得更加复杂，您可以考虑将它们捆绑到您自己的新 main 方法中，或者甚至创建一个单独的 get_role 方法，例如，但现在这很短也很简单，在这里没问题。
基本规则是：首先在顶层定义您的类和函数等，然后然后使用您想要的任何控制流逻辑来决定调用什么、如何调用以及何时调用.您可能最终想要在条件和/或函数中定义类是有原因的，但这是非常不寻常的，并且适用于复杂的情况。