deer-flow

The HTML element creates a disclosure widget in which information is visible only when the widget is toggled into an open state. A summary or label must be provided using the element.

[HDU 1532] (http://acm.hdu.edu.cn/showproblem.php?pid=1532) 题目描述： Drainage Ditches（排水沟） Time Limit: 2000/1000 MS (Java/Others) Memory Limit: 65536/327

The HTML element represents a section of a page whose purpose is to provide navigation links, either within the current document or to other documents. Common examples of navigation sections are menus, tables of contents, and indexes.