add optional component

content/6_Plat/1DSRQ.md

@@ -20,9 +20,13 @@ Consider the case when $\ominus$ denotes `min`.
  - CPH 9.1
  - [cp-algorithms RMQ](https://cp-algorithms.com/sequences/rmq.html)
 
+<optional-content title="Preprocessing in O(N)">
+
 In fact, preprocessing can be done in $O(N)$ time.
 
  - [$O(1)$ Query RMQ with $O(N)$ build](https://codeforces.com/blog/entry/78931)
+ 
+</optional-content>
 
 ### Divide & Conquer
 

gatsby-browser.tsx

@@ -79,6 +79,23 @@ const components = {
       </div>
     </div>
   ),
+  'optional-content': ({
+    children,
+    title,
+  }: {
+    children: React.ReactNode;
+    title?: string;
+  }) => (
+    <div className="bg-white overflow-hidden shadow rounded-lg border border-purple-400 my-2">
+      <div className="p-4 flex items-center font-medium text-purple-800 bg-purple-50">
+        <svg className="h-6 w-6 mr-3" fill="currentColor" viewBox="0 0 20 20">
+          <path d="M11 3a1 1 0 10-2 0v1a1 1 0 102 0V3zM15.657 5.757a1 1 0 00-1.414-1.414l-.707.707a1 1 0 001.414 1.414l.707-.707zM18 10a1 1 0 01-1 1h-1a1 1 0 110-2h1a1 1 0 011 1zM5.05 6.464A1 1 0 106.464 5.05l-.707-.707a1 1 0 00-1.414 1.414l.707.707zM5 10a1 1 0 01-1 1H3a1 1 0 110-2h1a1 1 0 011 1zM8 16v-1h4v1a2 2 0 11-4 0zM12 14c.015-.34.208-.646.477-.859a4 4 0 10-4.954 0c.27.213.462.519.476.859h4.002z" />
+        </svg>
+        Optional{title ? `: ${title}` : ''}
+      </div>
+      <div className="px-4 pt-5 pb-2 sm:p-6 sm:pb-2">{children}</div>
+    </div>
+  ),
 };
 
 export const wrapRootElement = ({ element }) => (