问题描述：n个任务分配给n个人，任务j分配给人i的成本是C[i,j]，希望完成所有任务的成本最低，算法如何设计？

★编程任务：给定任务表示如下表，编程计算所需完成任务最低的成本。

★数据输入：输入数据由文件名为input.txt的文本文件提供。文件的第1行为任务总数（人数）n；在接下来的n行中，每行有n个自然数，表示成本。

★结果输出: 程序运行结束时，将计算结果输出到文件output.txt中。

-Problem Descr iption: n tasks assigned to n individual task j allocated gives i cost C [i, j], lowest cost hope to complete all the tasks, how to design algorithms? ★ programming task: given task following table programming calculation required to complete the task at the lowest cost. ★ Data Input: input data from a text file named input.txt file. File of the first acts of the total number of tasks (number) n　in the next n lines, each line n natural numbers, said the cost. ★ results output: the end of the program runs, the calculation results output to the file output.txt.