Add solution #397

Author: JoshCrozier

README.md

@@ -315,6 +315,7 @@
 394|[Decode String](./0394-decode-string.js)|Medium|
 395|[Longest Substring with At Least K Repeating Characters](./0395-longest-substring-with-at-least-k-repeating-characters.js)|Medium|
 396|[Rotate Function](./0396-rotate-function.js)|Medium|
+397|[Integer Replacement](./0397-integer-replacement.js)|Medium|
 399|[Evaluate Division](./0399-evaluate-division.js)|Medium|
 404|[Sum of Left Leaves](./0404-sum-of-left-leaves.js)|Easy|
 405|[Convert a Number to Hexadecimal](./0405-convert-a-number-to-hexadecimal.js)|Easy|

solutions/0397-integer-replacement.js

@@ -0,0 +1,29 @@
+/**
+ * 397. Integer Replacement
+ * https://leetcode.com/problems/integer-replacement/
+ * Difficulty: Medium
+ *
+ * Given a positive integer n, you can apply one of the following operations:
+ * 1. If n is even, replace n with n / 2.
+ * 2. If n is odd, replace n with either n + 1 or n - 1.
+ *
+ * Return the minimum number of operations needed for n to become 1.
+ */
+
+/**
+ * @param {number} n
+ * @return {number}
+ */
+/**
+ * @param {number} n
+ * @param {number} count
+ * @return {number}
+ */
+var integerReplacement = function(n, count = 0) {
+  if (n === 1) return count;
+  if (n % 2 === 0) {
+    return integerReplacement(n / 2, count + 1);
+  } else {
+    return Math.min(integerReplacement(n + 1, count + 1), integerReplacement(n - 1, count + 1));
+  }
+};