Add solution #240

Author: JoshCrozier

README.md

@@ -216,6 +216,7 @@
 237|[Delete Node in a Linked List](./0237-delete-node-in-a-linked-list.js)|Easy|
 238|[Product of Array Except Self](./0238-product-of-array-except-self.js)|Medium|
 239|[Sliding Window Maximum](./0239-sliding-window-maximum.js)|Hard|
+240|[Search a 2D Matrix II](./0240-search-a-2d-matrix-ii.js)|Medium|
 242|[Valid Anagram](./0242-valid-anagram.js)|Easy|
 257|[Binary Tree Paths](./0257-binary-tree-paths.js)|Easy|
 258|[Add Digits](./0258-add-digits.js)|Easy|

solutions/0240-search-a-2d-matrix-ii.js

@@ -0,0 +1,25 @@
+/**
+ * 240. Search a 2D Matrix II
+ * https://leetcode.com/problems/search-a-2d-matrix-ii/
+ * Difficulty: Medium
+ *
+ * Write an efficient algorithm that searches for a value target in an m x n integer matrix
+ * matrix. This matrix has the following properties:
+ * - Integers in each row are sorted in ascending from left to right.
+ * - Integers in each column are sorted in ascending from top to bottom.
+ */
+
+/**
+ * @param {number[][]} matrix
+ * @param {number} target
+ * @return {boolean}
+ */
+var searchMatrix = function(matrix, target) {
+  for (let i = 0, j = matrix[0].length - 1; i < matrix.length && j >= 0;) {
+    if (matrix[i][j] === target) {
+      return true;
+    }
+    matrix[i][j] > target ? j-- : i++;
+  }
+  return false;
+};