Add solution #541

Author: JoshCrozier

README.md

@@ -19,6 +19,7 @@
 387|[First Unique Character in a String](./0387-first-unique-character-in-a-string.js)|Easy|
 451|[Sort Characters By Frequency](./0451-sort-characters-by-frequency.js)|Medium|
 459|[Repeated Substring Pattern](./0459-repeated-substring-pattern.js)|Easy|
+541|[Reverse String II](./0541-reverse-string-ii.js)|Easy|
 606|[Construct String from Binary Tree](./0606-construct-string-from-binary-tree.js)|Easy|
 617|[Merge Two Binary Trees](./0617-merge-two-binary-trees.js)|Easy|
 648|[Replace Words](./0648-replace-words.js)|Medium|

solutions/0541-reverse-string-ii.js

@@ -0,0 +1,24 @@
+/**
+ * 541. Reverse String II
+ * https://leetcode.com/problems/reverse-string-ii/
+ * Difficulty: Easy
+ *
+ * Given a string and an integer k, you need to reverse the first k characters
+ * for every 2k characters counting from the start of the string. If there are
+ * less than k characters left, reverse all of them. If there are less than 2k
+ * but greater than or equal to k characters, then reverse the first k
+ * characters and left the other as original.
+ */
+
+/**
+ * @param {string} s
+ * @param {number} k
+ * @return {string}
+ */
+var reverseStr = function(s, k) {
+  const split = s.split('');
+  for (let i = 0; i < s.length; i += 2 * k) {
+    split.splice(i, 0, ...split.splice(i, k).reverse());
+  }
+  return split.join('');
+};