From cc621f1fddac7391389270d7bc38326507b4b495 Mon Sep 17 00:00:00 2001
From: parth-6945 <140963864+parth-6945@users.noreply.github.com>
Date: Mon, 14 Apr 2025 23:31:29 +0530
Subject: [PATCH] Add find_unique_number algorithm to bit manipulation (#12654)

* Add find_unique_number algorithm to bit manipulation

* [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

---------

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>
---
 bit_manipulation/find_unique_number.py | 37 ++++++++++++++++++++++++++
 1 file changed, 37 insertions(+)
 create mode 100644 bit_manipulation/find_unique_number.py

diff --git a/bit_manipulation/find_unique_number.py b/bit_manipulation/find_unique_number.py
new file mode 100644
index 000000000..77970b486
--- /dev/null
+++ b/bit_manipulation/find_unique_number.py
@@ -0,0 +1,37 @@
+def find_unique_number(arr: list[int]) -> int:
+    """
+    Given a list of integers where every element appears twice except for one,
+    this function returns the element that appears only once using bitwise XOR.
+
+    >>> find_unique_number([1, 1, 2, 2, 3])
+    3
+    >>> find_unique_number([4, 5, 4, 6, 6])
+    5
+    >>> find_unique_number([7])
+    7
+    >>> find_unique_number([10, 20, 10])
+    20
+    >>> find_unique_number([])
+    Traceback (most recent call last):
+        ...
+    ValueError: input list must not be empty
+    >>> find_unique_number([1, 'a', 1])
+    Traceback (most recent call last):
+        ...
+    TypeError: all elements must be integers
+    """
+    if not arr:
+        raise ValueError("input list must not be empty")
+    if not all(isinstance(x, int) for x in arr):
+        raise TypeError("all elements must be integers")
+
+    result = 0
+    for num in arr:
+        result ^= num
+    return result
+
+
+if __name__ == "__main__":
+    import doctest
+
+    doctest.testmod()