Add solution #1233

Author: JoshCrozier

README.md

@@ -46,6 +46,7 @@
 1189|[Maximum Number of Balloons](./1189-maximum-number-of-balloons.js)|Easy|
 1207|[Unique Number of Occurrences](./1207-unique-number-of-occurrences.js)|Easy|
 1232|[Check If It Is a Straight Line](./1232-check-if-it-is-a-straight-line.js)|Easy|
+1233|[Remove Sub-Folders from the Filesystem](./1233-remove-sub-folders-from-the-filesystem.js)|Medium|
 1249|[Minimum Remove to Make Valid Parentheses](./1249-minimum-remove-to-make-valid-parentheses.js)|Medium|
 1252|[Cells with Odd Values in a Matrix](./1252-cells-with-odd-values-in-a-matrix.js)|Easy|
 1287|[Element Appearing More Than 25% In Sorted Array](./1287-element-appearing-more-than-25-in-sorted-array.js)|Easy|

solutions/1233-remove-sub-folders-from-the-filesystem.js

@@ -0,0 +1,32 @@
+/**
+ * 1233. Remove Sub-Folders from the Filesystem
+ * https://leetcode.com/problems/remove-sub-folders-from-the-filesystem/
+ * Difficulty: Medium
+ *
+ * Given a list of folders, remove all sub-folders in those folders
+ * and return in any order the folders after removing.
+ *
+ * If a folder[i] is located within another folder[j], it is called
+ * a sub-folder of it. The format of a path is one or more concatenated
+ * strings of the form: / followed by one or more lowercase English
+ * letters. For example, /leetcode and /leetcode/problems are valid
+ * paths while an empty string and / are not.
+ */
+
+/**
+ * @param {string[]} folder
+ * @return {string[]}
+ */
+var removeSubfolders = function(folder) {
+  const set = new Set(folder);
+  return folder.filter(path => !getPathSegments(path).some(p => set.has(p)));
+};
+
+function getPathSegments(path) {
+  const split = path.split('/');
+  const segments = [split.shift()];
+  while (split.length > 1) {
+    segments.push(segments[segments.length - 1] + '/' + split.shift());
+  }
+  return segments;
+}