java金字塔的实现，包括倒金字塔，直角三角形-Pyramid java implementation, including the inverted pyramid, triangle

面试的笔试题目：打印乘法表、打印金字塔（几种不同的方式）、大小写字母转换-Interview the written topic: print the multiplication tables、 Print the pyramid(several different ways) 、uppercase conversion