真实世界是复杂的，软件也同样。为了解决一个复杂问题，一个好的策略是将它分解为较简单的部分，将一个大程序分解为一组较小的函数。这称为自顶向下分析或有时叫做逐步求精。本次实验将练习采用多个函数实现一个较复杂的问题——打印1900年后任意指定年份的日历，用以下格式显示每个月。-The real world is complex, the software as well. In order to solve a complex problem, a good strategy is to break it down into a simple parts, will be a big program into a group of lesser function. This is called the top-down analysis or sometimes called gradually refinement. The experiment will practice more than the function for a more complex problem--print 1900 years later any designated the calendar year, with the following format shows each month.