[Project Euler] Fix code style in Problem 41

project_euler/problem_41/sol1.py

@@ -4,14 +4,15 @@
 from math import sqrt
 
 """
+Pandigital prime
+Problem 41: https://projecteuler.net/problem=41
+
 We shall say that an n-digit number is pandigital if it makes use of all the digits
 1 to n exactly once. For example, 2143 is a 4-digit pandigital and is also prime.
 What is the largest n-digit pandigital prime that exists?
-"""
 
-"""
 All pandigital numbers except for 1, 4 ,7 pandigital numbers are divisible by 3.
-So we will check only 7 digit panddigital numbers to obtain the largest possible
+So we will check only 7 digit pandigital numbers to obtain the largest possible
 pandigital prime.
 """
 
@@ -37,18 +38,31 @@ def is_prime(n: int) -> bool:
 
 def compute_pandigital_primes(n: int) -> list[int]:
     """
-    Returns a list of all n-digit pandigital primes.
+    Returns a list of all pandigital prime numbers of length n.
     >>> compute_pandigital_primes(2)
     []
-    >>> max(compute_pandigital_primes(4))
-    4231
-    >>> max(compute_pandigital_primes(7))
-    7652413
+    >>> compute_pandigital_primes(4)
+    [1423, 2143, 2341, 4231]
     """
     pandigital_str = "".join(str(i) for i in range(1, n + 1))
     perm_list = [int("".join(i)) for i in permutations(pandigital_str, n)]
     return [num for num in perm_list if is_prime(num)]
 
 
+def solution(n: int = 7) -> int:
+    """
+    Returns the maximum pandigital prime number of length n
+    If no pandigitals exist the returned value is zero.
+    >>> solution(2)
+    0
+    >>> solution(4)
+    4231
+    >>> solution(7)
+    7652413
+    """
+    pandigital_primes = compute_pandigital_primes(n)
+    return max(pandigital_primes) if pandigital_primes else 0
+
+
 if __name__ == "__main__":
-    print(f"{max(compute_pandigital_primes(7)) = }")
+    print(f"{solution()}")