调度问题的回溯算法，算法中的经典问题。问题描述：假设有n个任务由k个可并行工作的机器完成。完成任务i需要的时间为ti。试设计一个算法找出完成这n个任务的最佳调度，使得完成全部任务的时间最早。-Scheduling problem backtracking algorithm is the classic problem. Problem Descr iption: Suppose there are n-task by the k-parallel machine can be completed. The time required to complete the task i is ti. Try to design an algorithm to find completing these n-best task scheduling, making the earliest time to complete all tasks.