标签：self bsp tco isp ems ber 个数 solution splay
https://leetcode-cn.com/problems/count-of-smaller-numbers-after-self/solution/gui-bing-pai-xu-suo-yin-shu-zu-python-dai-ma-java-/
leetcode315 计算右侧小于当前元素的个数
原文地址：https://www.cnblogs.com/joelwang/p/11896881.html
