Add solution #645

Author: JoshCrozier

0645-set-mismatch.js

@@ -0,0 +1,40 @@
+/**
+ * 645. Set Mismatch
+ * https://leetcode.com/problems/set-mismatch/
+ * Difficulty: Medium
+ *
+ * You have a set of integers s, which originally contains all the numbers from 1 to n.
+ * Unfortunately, due to some error, one of the numbers in s got duplicated to another
+ * number in the set, which results in repetition of one number and loss of another number.
+ *
+ * You are given an integer array nums representing the data status of this set after
+ * the error.
+ *
+ * Find the number that occurs twice and the number that is missing and return them in
+ * the form of an array.
+ */
+
+/**
+ * @param {number[]} nums
+ * @return {number[]}
+ */
+var findErrorNums = function(nums) {
+  const set = new Set();
+  const result = [];
+
+  for (const n of nums) {
+    if (set.has(n)) {
+      result.push(n);
+    }
+    set.add(n);
+  }
+
+  for (let i = nums.length; i > 0; i--) {
+    if (!set.has(i)) {
+      result.push(i);
+      break;
+    }
+  }
+
+  return result;
+};

README.md

@@ -132,6 +132,7 @@
 606|[Construct String from Binary Tree](./0606-construct-string-from-binary-tree.js)|Easy|
 617|[Merge Two Binary Trees](./0617-merge-two-binary-trees.js)|Easy|
 628|[Maximum Product of Three Numbers](./0628-maximum-product-of-three-numbers.js)|Easy|
+645|[Set Mismatch](./0645-set-mismatch.js)|Medium|
 648|[Replace Words](./0648-replace-words.js)|Medium|
 653|[Two Sum IV - Input is a BST](./0653-two-sum-iv-input-is-a-bst.js)|Easy|
 686|[Repeated String Match](./0686-repeated-string-match.js)|Easy|