Add solution #3289

Author: JoshCrozier

README.md

@@ -2695,6 +2695,7 @@
 3272|[Find the Count of Good Integers](./solutions/3272-find-the-count-of-good-integers.js)|Hard|
 3279|[Maximum Total Area Occupied by Pistons](./solutions/3279-maximum-total-area-occupied-by-pistons.js)|Hard|
 3284|[Sum of Consecutive Subarrays](./solutions/3284-sum-of-consecutive-subarrays.js)|Medium|
+3289|[The Two Sneaky Numbers of Digitville](./solutions/3289-the-two-sneaky-numbers-of-digitville.js)|Easy|
 3294|[Convert Doubly Linked List to Array II](./solutions/3294-convert-doubly-linked-list-to-array-ii.js)|Medium|
 3299|[Sum of Consecutive Subsequences](./solutions/3299-sum-of-consecutive-subsequences.js)|Hard|
 3304|[Find the K-th Character in String Game I](./solutions/3304-find-the-k-th-character-in-string-game-i.js)|Easy|

solutions/3289-the-two-sneaky-numbers-of-digitville.js

@@ -0,0 +1,31 @@
+/**
+ * 3289. The Two Sneaky Numbers of Digitville
+ * https://leetcode.com/problems/the-two-sneaky-numbers-of-digitville/
+ * Difficulty: Easy
+ *
+ * In the town of Digitville, there was a list of numbers called nums containing integers
+ * from 0 to n - 1. Each number was supposed to appear exactly once in the list, however,
+ * two mischievous numbers sneaked in an additional time, making the list longer than usual.
+ *
+ * As the town detective, your task is to find these two sneaky numbers. Return an array of
+ * size two containing the two numbers (in any order), so peace can return to Digitville.
+ */
+
+/**
+ * @param {number[]} nums
+ * @return {number[]}
+ */
+var getSneakyNumbers = function(nums) {
+  const set = new Set();
+  const result = [];
+
+  for (const n of nums) {
+    if (set.has(n)) {
+      result.push(n);
+    } else {
+      set.add(n);
+    }
+  }
+
+  return result;
+};