Add solution #3019

Author: JoshCrozier

README.md

@@ -2132,6 +2132,7 @@
 3014|[Minimum Number of Pushes to Type Word I](./solutions/3014-minimum-number-of-pushes-to-type-word-i.js)|Easy|
 3015|[Count the Number of Houses at a Certain Distance I](./solutions/3015-count-the-number-of-houses-at-a-certain-distance-i.js)|Medium|
 3016|[Minimum Number of Pushes to Type Word II](./solutions/3016-minimum-number-of-pushes-to-type-word-ii.js)|Medium|
+3019|[Number of Changing Keys](./solutions/3019-number-of-changing-keys.js)|Easy|
 3024|[Type of Triangle](./solutions/3024-type-of-triangle.js)|Easy|
 3042|[Count Prefix and Suffix Pairs I](./solutions/3042-count-prefix-and-suffix-pairs-i.js)|Easy|
 3066|[Minimum Operations to Exceed Threshold Value II](./solutions/3066-minimum-operations-to-exceed-threshold-value-ii.js)|Medium|

solutions/3019-number-of-changing-keys.js

@@ -0,0 +1,30 @@
+/**
+ * 3019. Number of Changing Keys
+ * https://leetcode.com/problems/number-of-changing-keys/
+ * Difficulty: Easy
+ *
+ * You are given a 0-indexed string s typed by a user. Changing a key is defined as using a key
+ * different from the last used key. For example, s = "ab" has a change of a key while s = "bBBb"
+ * does not have any.
+ *
+ * Return the number of times the user had to change the key.
+ *
+ * Note: Modifiers like shift or caps lock won't be counted in changing the key that is if a user
+ * typed the letter 'a' and then the letter 'A' then it will not be considered as a changing of key.
+ */
+
+/**
+ * @param {string} s
+ * @return {number}
+ */
+var countKeyChanges = function(s) {
+  let result = 0;
+
+  for (let i = 1; i < s.length; i++) {
+    if (s[i].toLowerCase() !== s[i - 1].toLowerCase()) {
+      result++;
+    }
+  }
+
+  return result;
+};