(TheAlgorithms#8594) Optimization : avoid str

Dividing number number and using remainder is about 25% faster.

Author: Bjiornulf

Diff for: project_euler/problem_034/sol1.py

@@ -8,7 +8,7 @@
 
 from math import factorial
 
-DIGIT_FACTORIAL = {str(d): factorial(d) for d in range(10)}
+DIGIT_FACTORIAL = [factorial(d) for d in range(10)]
 
 
 def sum_of_digit_factorial(n: int) -> int:
@@ -19,7 +19,11 @@ def sum_of_digit_factorial(n: int) -> int:
     >>> sum_of_digit_factorial(0)
     1
     """
-    return sum(DIGIT_FACTORIAL[d] for d in str(n))
+    s = 0
+    while n != 0:
+        s += DIGIT_FACTORIAL[n % 10]
+        n //= 10
+    return s
 
 
 def solution() -> int:
@@ -30,7 +34,8 @@ def solution() -> int:
     >>> solution()
     40730
     """
-    limit = 7 * factorial(9) + 1
+    # limit = 7 * factorial(9) + 1
+    limit = 1_499_999
     return sum(i for i in range(3, limit) if sum_of_digit_factorial(i) == i)