优点：输出在 (−1,1)，比 sigmoid 居中，对梯度更友好
Easy difficulty hints, answers for Feb. 27 PipsEqual (6): Everything in this purple space must be equal to 6. The answer is 6-0, placed horizontally; 6-3, placed vertically.
，这一点在爱思助手下载最新版本中也有详细论述
2️⃣ 选择排序 (Selection Sort)。业内人士推荐91视频作为进阶阅读
习题链接：LeetCode 581. 最短无序连续子数组