Add solution #1982

Author: JoshCrozier

README.md

@@ -1,4 +1,4 @@
-# 1,668 LeetCode solutions in JavaScript
+# 1,669 LeetCode solutions in JavaScript
 
 [https://leetcodejavascript.com](https://leetcodejavascript.com)
 
@@ -1521,6 +1521,7 @@
 1979|[Find Greatest Common Divisor of Array](./solutions/1979-find-greatest-common-divisor-of-array.js)|Easy|
 1980|[Find Unique Binary String](./solutions/1980-find-unique-binary-string.js)|Medium|
 1981|[Minimize the Difference Between Target and Chosen Elements](./solutions/1981-minimize-the-difference-between-target-and-chosen-elements.js)|Medium|
+1982|[Find Array Given Subset Sums](./solutions/1982-find-array-given-subset-sums.js)|Hard|
 1985|[Find the Kth Largest Integer in the Array](./solutions/1985-find-the-kth-largest-integer-in-the-array.js)|Medium|
 1996|[The Number of Weak Characters in the Game](./solutions/1996-the-number-of-weak-characters-in-the-game.js)|Medium|
 2000|[Reverse Prefix of Word](./solutions/2000-reverse-prefix-of-word.js)|Easy|

solutions/1982-find-array-given-subset-sums.js

@@ -0,0 +1,63 @@
+/**
+ * 1982. Find Array Given Subset Sums
+ * https://leetcode.com/problems/find-array-given-subset-sums/
+ * Difficulty: Hard
+ *
+ * You are given an integer n representing the length of an unknown array that you are trying
+ * to recover. You are also given an array sums containing the values of all 2n subset sums of
+ * the unknown array (in no particular order).
+ *
+ * Return the array ans of length n representing the unknown array. If multiple answers exist,
+ * return any of them.
+ *
+ * An array sub is a subset of an array arr if sub can be obtained from arr by deleting some
+ * (possibly zero or all) elements of arr. The sum of the elements in sub is one possible
+ * subset sum of arr. The sum of an empty array is considered to be 0.
+ *
+ * Note: Test cases are generated such that there will always be at least one correct answer.
+ */
+
+/**
+* @param {number} n
+* @param {number[]} sums
+* @return {number[]}
+*/
+var recoverArray = function(n, sums) {
+  sums.sort((a, b) => a - b);
+
+  const result = [];
+  while (result.length < n) {
+    const diff = sums[1] - sums[0];
+
+    const withNum = [];
+    const withoutNum = [];
+    const freq = new Map();
+    for (const sum of sums) {
+      freq.set(sum, (freq.get(sum) || 0) + 1);
+    }
+
+    for (const sum of sums) {
+      if (freq.get(sum) > 0) {
+        freq.set(sum, freq.get(sum) - 1);
+
+        if (freq.get(sum + diff) > 0) {
+          freq.set(sum + diff, freq.get(sum + diff) - 1);
+          withoutNum.push(sum);
+          withNum.push(sum + diff);
+        } else {
+          return [];
+        }
+      }
+    }
+
+    if (withoutNum.includes(0)) {
+      result.push(diff);
+      sums = withoutNum;
+    } else {
+      result.push(-diff);
+      sums = withNum;
+    }
+  }
+
+  return result;
+};