From e1be882f72f85d5f7267b46f0ffd5203a6d81e2e Mon Sep 17 00:00:00 2001
From: Akshay Dubey <38462415+itsAkshayDubey@users.noreply.github.com>
Date: Thu, 10 Nov 2022 16:25:50 +0530
Subject: [PATCH] algorithm: Twin prime (#7980)
* feat: Add twin prime algorithm
* [pre-commit.ci] auto fixes from pre-commit.com hooks
for more information, see https://pre-commit.ci
* fix: Fix broken import statement
Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>
---
maths/twin_prime.py | 45 +++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 45 insertions(+)
create mode 100644 maths/twin_prime.py
diff --git a/maths/twin_prime.py b/maths/twin_prime.py
new file mode 100644
index 00000000..e6ac0cc7
--- /dev/null
+++ b/maths/twin_prime.py
@@ -0,0 +1,45 @@
+"""
+== Twin Prime ==
+A number n+2 is said to be a Twin prime of number n if
+both n and n+2 are prime.
+
+Examples of Twin pairs: (3, 5), (5, 7), (11, 13), (17, 19), (29, 31), (41, 43), ...
+https://en.wikipedia.org/wiki/Twin_prime
+"""
+
+# Author : Akshay Dubey (https://github.com/itsAkshayDubey)
+from maths.prime_check import is_prime
+
+
+def twin_prime(number: int) -> int:
+ """
+ # doctest: +NORMALIZE_WHITESPACE
+ This functions takes an integer number as input.
+ returns n+2 if n and n+2 are prime numbers and -1 otherwise.
+ >>> twin_prime(3)
+ 5
+ >>> twin_prime(4)
+ -1
+ >>> twin_prime(5)
+ 7
+ >>> twin_prime(17)
+ 19
+ >>> twin_prime(0)
+ -1
+ >>> twin_prime(6.0)
+ Traceback (most recent call last):
+ ...
+ TypeError: Input value of [number=6.0] must be an integer
+ """
+ if not isinstance(number, int):
+ raise TypeError(f"Input value of [number={number}] must be an integer")
+ if is_prime(number) and is_prime(number + 2):
+ return number + 2
+ else:
+ return -1
+
+
+if __name__ == "__main__":
+ import doctest
+
+ doctest.testmod()