Add solution #2624

Author: JoshCrozier

README.md

@@ -1,4 +1,4 @@
-# 1,460 LeetCode solutions in JavaScript
+# 1,461 LeetCode solutions in JavaScript
 
 [https://leetcodejavascript.com](https://leetcodejavascript.com)
 
@@ -1394,6 +1394,7 @@
 2621|[Sleep](./solutions/2621-sleep.js)|Easy|
 2622|[Cache With Time Limit](./solutions/2622-cache-with-time-limit.js)|Medium|
 2623|[Memoize](./solutions/2623-memoize.js)|Medium|
+2624|[Snail Traversal](./solutions/2624-snail-traversal.js)|Medium|
 2625|[Flatten Deeply Nested Array](./solutions/2625-flatten-deeply-nested-array.js)|Medium|
 2626|[Array Reduce Transformation](./solutions/2626-array-reduce-transformation.js)|Easy|
 2627|[Debounce](./solutions/2627-debounce.js)|Medium|

solutions/2624-snail-traversal.js

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+/**
+ * 2624. Snail Traversal
+ * https://leetcode.com/problems/snail-traversal/
+ * Difficulty: Medium
+ *
+ * Write code that enhances all arrays such that you can call the snail(rowsCount,
+ * colsCount) method that transforms the 1D array into a 2D array organised in the
+ * pattern known as snail traversal order. Invalid input values should output an
+ * empty array. If rowsCount * colsCount !== nums.length, the input is considered invalid.
+ *
+ * Snail traversal order starts at the top left cell with the first value of the
+ * current array. It then moves through the entire first column from top to bottom,
+ * followed by moving to the next column on the right and traversing it from bottom
+ * to top. This pattern continues, alternating the direction of traversal with each
+ * column, until the entire current array is covered. For example, when given the
+ * input array [19, 10, 3, 7, 9, 8, 5, 2, 1, 17, 16, 14, 12, 18, 6, 13, 11, 20, 4, 15]
+ * with rowsCount = 5 and colsCount = 4, the desired output matrix is shown below.
+ * Note that iterating the matrix following the arrows corresponds to the order
+ * of numbers in the original array.
+ */
+
+/**
+ * @param {number} rowsCount
+ * @param {number} colsCount
+ * @return {Array<Array<number>>}
+ */
+Array.prototype.snail = function(rowsCount, colsCount) {
+  if (rowsCount * colsCount !== this.length) return [];
+
+  const result = Array.from({ length: rowsCount }, () => []);
+  let index = 0;
+
+  for (let col = 0; col < colsCount; col++) {
+    if (col % 2 === 0) {
+      for (let row = 0; row < rowsCount; row++) {
+        result[row][col] = this[index++];
+      }
+    } else {
+      for (let row = rowsCount - 1; row >= 0; row--) {
+        result[row][col] = this[index++];
+      }
+    }
+  }
+
+  return result;
+}