contents: reorganize algo cheatsheet

website/sidebars.js

@@ -54,26 +54,54 @@ module.exports = {
     {
       'Algorithms study cheatsheets': [
         'algorithms/study-cheatsheet',
+        {
+          type: 'category',
+          label: 'Basics',
+          collapsible: false,
+          items: [
             'algorithms/array',
             'algorithms/string',
             'algorithms/hash-table',
             'algorithms/recursion',
             'algorithms/sorting-searching',
+          ],
+        },
+        {
+          type: 'category',
+          label: 'Data structures',
+          collapsible: false,
+          items: [
             'algorithms/matrix',
             'algorithms/linked-list',
             'algorithms/queue',
             'algorithms/stack',
+            'algorithms/interval',
+          ],
+        },
+        {
+          type: 'category',
+          label: 'Advanced data structures',
+          collapsible: false,
+          items: [
             'algorithms/tree',
             'algorithms/graph',
             'algorithms/heap',
             'algorithms/trie',
-        'algorithms/interval',
+          ],
+        },
+        {
+          type: 'category',
+          label: 'Additional',
+          collapsible: false,
+          items: [
             'algorithms/dynamic-programming',
             'algorithms/binary',
             'algorithms/math',
             'algorithms/geometry',
           ],
         },
+      ],
+    },
     {
       Misc: ['interviewer-cheatsheet'],
     },