Add solution #1630

Author: JoshCrozier

README.md

@@ -1,4 +1,4 @@
-# 1,433 LeetCode solutions in JavaScript
+# 1,434 LeetCode solutions in JavaScript
 
 [https://leetcodejavascript.com](https://leetcodejavascript.com)
 
@@ -1257,6 +1257,7 @@
 1626|[Best Team With No Conflicts](./solutions/1626-best-team-with-no-conflicts.js)|Medium|
 1627|[Graph Connectivity With Threshold](./solutions/1627-graph-connectivity-with-threshold.js)|Hard|
 1629|[Slowest Key](./solutions/1629-slowest-key.js)|Easy|
+1630|[Arithmetic Subarrays](./solutions/1630-arithmetic-subarrays.js)|Medium|
 1657|[Determine if Two Strings Are Close](./solutions/1657-determine-if-two-strings-are-close.js)|Medium|
 1668|[Maximum Repeating Substring](./solutions/1668-maximum-repeating-substring.js)|Easy|
 1669|[Merge In Between Linked Lists](./solutions/1669-merge-in-between-linked-lists.js)|Medium|

solutions/1630-arithmetic-subarrays.js

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+/**
+ * 1630. Arithmetic Subarrays
+ * https://leetcode.com/problems/arithmetic-subarrays/
+ * Difficulty: Medium
+ *
+ * A sequence of numbers is called arithmetic if it consists of at least two elements, and the
+ * difference between every two consecutive elements is the same. More formally, a sequence s
+ * is arithmetic if and only if s[i+1] - s[i] == s[1] - s[0] for all valid i.
+ *
+ * For example, these are arithmetic sequences:
+ * - 1, 3, 5, 7, 9
+ * - 7, 7, 7, 7
+ * - 3, -1, -5, -9
+ *
+ * The following sequence is not arithmetic:
+ * - 1, 1, 2, 5, 7
+ *
+ * You are given an array of n integers, nums, and two arrays of m integers each, l and r,
+ * representing the m range queries, where the ith query is the range [l[i], r[i]]. All the
+ * arrays are 0-indexed.
+ *
+ * Return a list of boolean elements answer, where answer[i] is true if the subarray
+ * nums[l[i]], nums[l[i]+1], ... , nums[r[i]] can be rearranged to form an arithmetic
+ * sequence, and false otherwise.
+ */
+
+/**
+ * @param {number[]} nums
+ * @param {number[]} l
+ * @param {number[]} r
+ * @return {boolean[]}
+ */
+var checkArithmeticSubarrays = function(nums, l, r) {
+  return l.map((start, index) => {
+    const end = r[index];
+    const subarray = nums.slice(start, end + 1);
+    return isArithmetic(subarray);
+  });
+
+  function isArithmetic(subarray) {
+    if (subarray.length < 2) return false;
+    subarray.sort((a, b) => a - b);
+    const diff = subarray[1] - subarray[0];
+    for (let i = 2; i < subarray.length; i++) {
+      if (subarray[i] - subarray[i - 1] !== diff) return false;
+    }
+    return true;
+  }
+};