Add the urlify algorithm

Author: FSou1

README.md

@@ -29,6 +29,7 @@ An algorithm is a finite sequence of well-defined, computer-implementable instru
   * [Document distance](src/algorithms/string/document-distance) - measure similarity between two strings;
   * [Is unique](src/algorithms/string/unique) - check a string for uniqueness;
   * [Check permutation](src/algorithms/string/permutation) - check if a string is a permutation of the other;
+  * [URLify](src/algorithms/string/urlify) - replace all spaces in a string with '%20';
 * **Sort**
   * [Insertion sort](src/algorithms/sort/insertion/simple) - sort an array with a simple insertion algorithm;
   * [Merge sort](src/algorithms/sort/merge) - sort an array with a merge sort algorithm;

src/algorithms/string/urlify/README.md

@@ -0,0 +1,3 @@
+# URLify
+
+Write a method to replace all spaces in a string with '%20'.

src/algorithms/string/urlify/__tests__/urlify.test.ts

@@ -0,0 +1,12 @@
+import { urlify } from "../urlify";
+
+test.each([
+  ["Mr John Smith      ", 13, "Mr%20John%20Smith"],
+  ["Hey", 3, "Hey"],
+  ["L o L", 5, "L%20o%20L"]
+])(
+  "if you urlify the %p string of %p len you should get '%p'",
+  (input, len, value) => {
+    expect(urlify(input, len)).toBe(value);
+  },
+);

src/algorithms/string/urlify/urlify.ts

@@ -0,0 +1,13 @@
+/**
+ * Replace all spaces in a string with '%20'
+ * @param  {string} input
+ * @param  {number} len
+ * @returns string
+ */
+export function urlify(input: string, len: number): string {
+  return input
+    .split("")
+    .map((el) => el === " " ? "%20" : el)
+    .filter((v, i) => i < len)
+    .join('');
+}