Add solution #3028

Author: JoshCrozier

README.md

@@ -2137,6 +2137,7 @@
 3024|[Type of Triangle](./solutions/3024-type-of-triangle.js)|Easy|
 3025|[Find the Number of Ways to Place People I](./solutions/3025-find-the-number-of-ways-to-place-people-i.js)|Medium|
 3027|[Find the Number of Ways to Place People II](./solutions/3027-find-the-number-of-ways-to-place-people-ii.js)|Hard|
+3028|[Ant on the Boundary](./solutions/3028-ant-on-the-boundary.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|
 3068|[Find the Maximum Sum of Node Values](./solutions/3068-find-the-maximum-sum-of-node-values.js)|Hard|

solutions/3028-ant-on-the-boundary.js

@@ -0,0 +1,38 @@
+/**
+ * 3028. Ant on the Boundary
+ * https://leetcode.com/problems/ant-on-the-boundary/
+ * Difficulty: Easy
+ *
+ * An ant is on a boundary. It sometimes goes left and sometimes right.
+ *
+ * You are given an array of non-zero integers nums. The ant starts reading nums from the
+ * first element of it to its end. At each step, it moves according to the value of the
+ * current element:
+ * - If nums[i] < 0, it moves left by -nums[i] units.
+ * - If nums[i] > 0, it moves right by nums[i] units.
+ *
+ * Return the number of times the ant returns to the boundary.
+ *
+ * Notes:
+ * - There is an infinite space on both sides of the boundary.
+ * - We check whether the ant is on the boundary only after it has moved |nums[i]| units.
+ *   In other words, if the ant crosses the boundary during its movement, it does not count.
+ */
+
+/**
+ * @param {number[]} nums
+ * @return {number}
+ */
+var returnToBoundaryCount = function(nums) {
+  let position = 0;
+  let result = 0;
+
+  for (const step of nums) {
+    position += step;
+    if (position === 0) {
+      result++;
+    }
+  }
+
+  return result;
+};