// 易错点2：漏写stack.length判断 → 栈空时访问stack[-1]会报错
知道海明威怎么写《老人与海》吗？他每天停笔时，故意不写完一句话，就写半句，留半句。为什么？这样第二天早上，他就有个现成的开头可以接着写，灵感不会断片。他太懂怎么对付那个完美主义小鬼了。
。91视频对此有专业解读
srand(time(NULL)); // 初始化随机种子
The data shows that confusable risk is not a property of character pairs alone. It is a property of character pairs in a specific font. That has direct consequences for anyone building on the web.