Add solution #378

Author: JoshCrozier

README.md

@@ -266,6 +266,7 @@
 371|[Sum of Two Integers](./0371-sum-of-two-integers.js)|Medium|
 372|[Super Pow](./0372-super-pow.js)|Medium|
 374|[Guess Number Higher or Lower](./0374-guess-number-higher-or-lower.js)|Medium|
+378|[Kth Smallest Element in a Sorted Matrix](./0378-kth-smallest-element-in-a-sorted-matrix.js)|Medium|
 380|[Insert Delete GetRandom O(1)](./0380-insert-delete-getrandom-o1.js)|Medium|
 383|[Ransom Note](./0383-ransom-note.js)|Easy|
 387|[First Unique Character in a String](./0387-first-unique-character-in-a-string.js)|Easy|

solutions/0378-kth-smallest-element-in-a-sorted-matrix.js

@@ -0,0 +1,21 @@
+/**
+ * 378. Kth Smallest Element in a Sorted Matrix
+ * https://leetcode.com/problems/kth-smallest-element-in-a-sorted-matrix/
+ * Difficulty: Medium
+ *
+ * Given an n x n matrix where each of the rows and columns is sorted in ascending order,
+ * return the kth smallest element in the matrix.
+ *
+ * Note that it is the kth smallest element in the sorted order, not the kth distinct element.
+ *
+ * You must find a solution with a memory complexity better than O(n2).
+ */
+
+/**
+ * @param {number[][]} matrix
+ * @param {number} k
+ * @return {number}
+ */
+var kthSmallest = function(matrix, k) {
+  return matrix.flat().sort((a, b) => a - b)[k - 1];
+};