请python编程实现以下问题的贪心算法,问题是多处理器多任务调度问题
时间: 2024-10-13 17:11:05 浏览: 60
在Python中,可以使用贪心算法解决多处理器多任务调度问题的一个经典例子是所谓的"最小剩余作业优先"(Least Remaining Time First, LRTF)策略。这个策略通常用于任务调度,其中任务有不同的处理时间和优先级。下面是一个简单的示例,我们将任务存储在一个列表里,每个任务由一个元组表示,包含任务的执行时间(单位时间)和优先级。
```python
class Task:
def __init__(self, execution_time, priority):
self.execution_time = execution_time
self.priority = priority
def schedule_tasks(tasks, processors):
# 按照优先级降序排序任务
tasks.sort(key=lambda t: (t.priority, -t.execution_time))
processor_jobs = [[] for _ in range(processors)]
total_time = 0
for task in tasks:
if not any(job_list for job_list in processor_jobs if job_list): # 如果某个处理器有空闲时间
# 将任务分配给第一个空闲处理器
min_time_processor = next((i for i, job_list in enumerate(processor_jobs) if not job_list), None)
if min_time_processor is not None:
processor_jobs[min_time_processor].append(task)
total_time += task.execution_time
else: # 所有处理器都有工作
# 找到处理时间最短的任务并分配给当前忙碌的处理器中最耗时的那个
min_time_task = max((task_list[-1] for task_list in processor_jobs if task_list), key=lambda t: t.execution_time)
min_time_processor = processor_jobs.index(min_time_task)
processor_jobs[min_time_processor].append(task)
return total_time, processor_jobs
# 示例
tasks = [Task(5, 3), Task(2, 1), Task(4, 2), Task(6, 4)]
processors = 3
total_time, assignments = schedule_tasks(tasks, processors)
print(f"总完成时间: {total_time} 时间")
for processor, jobs in enumerate(assignments):
print(f"Processor {processor+1}: {', '.join(str(t) for t in jobs)}")
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