From 0816bfcddd782fe3a9933b3ae8cc397fc9b8b456 Mon Sep 17 00:00:00 2001
From: Pranav Rustagi <57594891+Pranav-Rustagi@users.noreply.github.com>
Date: Wed, 12 Oct 2022 06:55:25 +0530
Subject: [PATCH] chore(Javascript): single occurring element among duplicates
 (#969)

---
 algorithms/JavaScript/README.md                |  1 +
 .../src/arrays/single-occurring-element.js     | 18 ++++++++++++++++++
 algorithms/JavaScript/src/index.js             |  1 +
 3 files changed, 20 insertions(+)
 create mode 100644 algorithms/JavaScript/src/arrays/single-occurring-element.js

diff --git a/algorithms/JavaScript/README.md b/algorithms/JavaScript/README.md
index 7222c11a..56159de7 100644
--- a/algorithms/JavaScript/README.md
+++ b/algorithms/JavaScript/README.md
@@ -3,6 +3,7 @@
 ## Arrays
 
 - [Counting Inversions](src/arrays/counting-inversions.js)
+- [Single Occurring Element](src/arrays/single-occurring-element.js)
 
 ## Linked Lists
 
diff --git a/algorithms/JavaScript/src/arrays/single-occurring-element.js b/algorithms/JavaScript/src/arrays/single-occurring-element.js
new file mode 100644
index 00000000..1c8da89d
--- /dev/null
+++ b/algorithms/JavaScript/src/arrays/single-occurring-element.js
@@ -0,0 +1,18 @@
+// Problem: Given an array of integers,
+// every element appears twice except for one. Find that single one.
+// Space Complexity: O(1)
+// Time Complexity: O(n)
+
+function singleOccurringElement(arr) {
+  let result = 0;
+  for (const el of arr) {
+    result ^= el;
+  }
+  return result;
+}
+
+const arr = [2, 5, 7, 3, 1, 8, 8, 9, 4, 2, 7, 1, 4, 9, 5];
+console.log(singleOccurringElement(arr));
+
+// Input: [2, 5, 7, 3, 1, 8, 8, 9, 4, 2, 7, 1, 4, 9, 5]
+// Output: 3
diff --git a/algorithms/JavaScript/src/index.js b/algorithms/JavaScript/src/index.js
index a599f73b..5264890b 100644
--- a/algorithms/JavaScript/src/index.js
+++ b/algorithms/JavaScript/src/index.js
@@ -1,5 +1,6 @@
 // Arrays
 require('./arrays/counting-inversions');
+require('./arrays/single-occurring-element');
 
 // Linked Lists
 require('./linked-lists/singly');