引用 引用https://www.educative.io/courses/grokking-the-system-design-interview/m2ygV4E81AR#div-stylecolorblack-background-colore2f4c7-border-radius5px-padding5px1-why-do-we-need-url-shorteningdiv https://blog.csdn.net/nausealiu/article/details/102575857?utm_medium=distribute.pc_relevant.none-task-blog-title-1&spm=1001.2101.3001.4242