当a和b均为大于0的数时，计算直角三角形的面积s并返回，
当a和b的任一值，小于等于0，即不能构成三角形时，返回-1
Keyboard input two floating-point numbers as the two right triangle sides a and B,
Function fun completed:
When a and B are both numbers greater than 0, calculate the area s of the right triangle and return,
When any value of a and B is less than or equal to 0, i.e. cannot form a triangle, return - 1 (2020-05-23, C/C++, 1KB, 下载0次)
本文档是剑指offer这本书的源码实现，也是在找工作的过程中的刷题记录，大家可以下载学习，能通过牛客网测试。
This document refers to the source code implementation of offer book, but also in the process of looking for a job to brush the title record, you can download and learn, can pass the Niukee test. (2018-08-16, C/C++, 8KB, 下载3次)