Add solution #1764

Author: JoshCrozier

README.md

@@ -425,6 +425,7 @@
 1716|[Calculate Money in Leetcode Bank](./1716-calculate-money-in-leetcode-bank.js)|Easy|
 1732|[Find the Highest Altitude](./1732-find-the-highest-altitude.js)|Easy|
 1748|[Sum of Unique Elements](./1748-sum-of-unique-elements.js)|Easy|
+1764|[Form Array by Concatenating Subarrays of Another Array](./1764-form-array-by-concatenating-subarrays-of-another-array.js)|Medium|
 1765|[Map of Highest Peak](./1765-map-of-highest-peak.js)|Medium|
 1768|[Merge Strings Alternately](./1768-merge-strings-alternately.js)|Easy|
 1780|[Check if Number is a Sum of Powers of Three](./1780-check-if-number-is-a-sum-of-powers-of-three.js)|Medium|

solutions/1764-form-array-by-concatenating-subarrays-of-another-array.js

@@ -0,0 +1,37 @@
+/**
+ * 1764. Form Array by Concatenating Subarrays of Another Array
+ * https://leetcode.com/problems/form-array-by-concatenating-subarrays-of-another-array/
+ * Difficulty: Medium
+ *
+ * You are given a 2D integer array groups of length n. You are also given an integer array nums.
+ *
+ * You are asked if you can choose n disjoint subarrays from the array nums such that the ith
+ * subarray is equal to groups[i] (0-indexed), and if i > 0, the (i-1)th subarray appears before
+ * the ith subarray in nums (i.e. the subarrays must be in the same order as groups).
+ *
+ * Return true if you can do this task, and false otherwise.
+ *
+ * Note that the subarrays are disjoint if and only if there is no index k such that nums[k]
+ * belongs to more than one subarray. A subarray is a contiguous sequence of elements within
+ * an array.
+ */
+
+/**
+ * @param {number[][]} groups
+ * @param {number[]} nums
+ * @return {boolean}
+ */
+var canChoose = function(groups, nums) {
+  const rows = groups.map(row => ',' + row.join(',') + ',');
+  const joined = `,${nums.join(',')},`;
+
+  for (let i = 0, offset = 0; i < rows.length; i++) {
+    offset = joined.indexOf(rows[i], offset);
+    if (offset === -1) {
+      return false;
+    }
+    offset += rows[i].length - 1;
+  }
+
+  return true;
+};