C语言写的一个金融行业工作面试题随即抽取小程序，每次抽取三道题，其中包括两道必选题和一道随机题。-Then extract a small financial sector face questions written in C language program, each extracted three questions, including the two must be subject matter and a random question.

银行的实现问题的介绍问题以答谢不错的问题(The introduction of the bank's problems in order to acknowledge the good question)