Add type hints in problems 41-50

Python/p041.py

@@ -9,7 +9,7 @@ from projecteuler import is_pandigital, is_prime, timing
 
 
 @timing
-def p041():
+def p041() -> None:
     # 8- and 9-digit pandigital numbers can't be prime, because
     # 1+2+...+8=36, which is divisible by 3, and 36+9=45 which is
     # also divisible by 3, and therefore the whole number is divisible

Python/p042.py

@@ -15,13 +15,14 @@ import sys
 from projecteuler import timing
 
 
-def is_triang(n):
+def is_triang(n: int) -> bool:
     i = 1
     j = 1
 
     while j <= n:
         if n == j:
             return True
+
         i = i + 1
         j = j + i
 
@@ -29,7 +30,7 @@ def is_triang(n):
 
 
 @timing
-def p042():
+def p042() -> None:
     try:
         with open('p042_words.txt', 'r', encoding='utf-8') as fp:
             words = list(fp.readline().replace('"', '').split(','))

Python/p043.py

@@ -14,14 +14,14 @@
 # d8d9d10=289 is divisible by 17
 #
 # Find the sum of all 0 to 9 pandigital numbers with this property.
-
+from typing import Tuple
 from itertools import permutations
 
 from projecteuler import timing
 
 
 # Function to check if the value has the desired property.
-def has_property(n):
+def has_property(n: Tuple[str, ...]) -> bool:
     value = int(n[1]) * 100 + int(n[2]) * 10 + int(n[3])
 
     if value % 2 != 0:
@@ -65,15 +65,15 @@ def p043():
     # Find all the permutations
     perm = list(permutations('0123456789'))
 
-    sum_ = 0
+    _sum = 0
 
     # For each permutation, check if it has the required property
     for i in perm:
         if has_property(i):
-            sum_ = sum_ + int(''.join(map(str, i)))
+            _sum = _sum + int(''.join(map(str, i)))
 
     print('Project Euler, Problem 43')
-    print(f'Answer: {sum_}')
+    print(f'Answer: {_sum}')
 
 
 if __name__ == '__main__':

Python/p044.py

@@ -13,7 +13,7 @@ from projecteuler import is_pentagonal, timing
 
 
 @timing
-def p044():
+def p044() -> None:
     found = 0
     n = 2
 

Python/p045.py

@@ -14,7 +14,7 @@ from projecteuler import is_pentagonal, timing
 
 
 @timing
-def p045():
+def p045() -> None:
     found = 0
     i = 143
 

Python/p046.py

@@ -20,7 +20,7 @@ N = 10000
 primes = sieve(N)
 
 
-def goldbach(n):
+def goldbach(n: int) -> bool:
     # Check every prime smaller than n.
     for i in range(3, n, 2):
         if primes[i] == 1:
@@ -44,7 +44,7 @@ def goldbach(n):
 
 
 @timing
-def p046():
+def p046() -> None:
     found = 0
     i = 3
 

Python/p047.py

@@ -12,13 +12,14 @@
 # 646 = 2 × 17 × 19.
 #
 # Find the first four consecutive integers to have four distinct prime factors each. What is the first of these numbers?
+from typing import List
 
 from projecteuler import timing
 
 
 # Function using a modified sieve of Eratosthenes to count
 # the distinct prime factors of each number.
-def count_factors(n):
+def count_factors(n: int) -> List[int]:
     factors = [0] * n
     i = 2
 
@@ -32,7 +33,7 @@ def count_factors(n):
 
 
 @timing
-def p047():
+def p047() -> None:
     N = 150000
 
     factors = count_factors(N)

Python/p048.py

@@ -8,16 +8,16 @@ from projecteuler import timing
 
 
 @timing
-def p048():
+def p048() -> None:
-    sum_ = 0
+    _sum = 0
 
     # Simply calculate the sum of the powers
     for i in range(1, 1001):
         power = i ** i
-        sum_ = sum_ + power
+        _sum = _sum + power
 
     print('Project Euler, Problem 48')
-    print(f'Answer: {str(sum_)[-10:]}')
+    print(f'Answer: {str(_sum)[-10:]}')
 
 
 if __name__ == '__main__':

Python/p049.py

@@ -12,7 +12,7 @@ from projecteuler import sieve, timing
 
 
 @timing
-def p049():
+def p049() -> None:
     N = 10000
 
     primes = sieve(N)

Python/p050.py

@@ -14,12 +14,12 @@ from projecteuler import sieve, timing
 
 
 @timing
-def p050():
+def p050() -> None:
     N = 1000000
 
     primes = sieve(N)
 
-    max_ = 0
+    _max = 0
     max_p = 0
 
     # Starting from a prime i, add consecutive primes until the
@@ -31,32 +31,32 @@ def p050():
     i = 2
     j = i + 1
     count = 1
-    sum_ = i
+    _sum = i
 
-    while j < N and sum_ < N:
+    while j < N and _sum < N:
         if primes[j] == 1:
-            sum_ = sum_ + j
+            _sum = _sum + j
             count = count + 1
 
-            if sum_ < N and primes[sum_] == 1 and count > max_:
+            if _sum < N and primes[_sum] == 1 and count > _max:
-                max_ = count
+                _max = count
-                max_p = sum
+                max_p = _sum
         j = j + 1
 
     for i in range(3, N, 2):
         if primes[i] == 1:
             count = 1
-            sum_ = i
+            _sum = i
             j = i + 2
 
-            while j < N and sum_ < N:
+            while j < N and _sum < N:
                 if primes[j] == 1:
-                    sum_ = sum_ + j
+                    _sum = _sum + j
                     count = count + 1
 
-                    if sum_ < N and primes[sum_] == 1 and count > max_:
+                    if _sum < N and primes[_sum] == 1 and count > _max:
-                        max_ = count
+                        _max = count
-                        max_p = sum_
+                        max_p = _sum
 
                 j = j + 2