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Changes functions name, add type hints and default args to problems 15 and 34 #3076

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47 changes: 18 additions & 29 deletions project_euler/problem_15/sol1.py
Original file line number Diff line number Diff line change
@@ -1,39 +1,28 @@
"""
Problem 15: https://projecteuler.net/problem=15

Starting in the top left corner of a 2×2 grid, and only being able to move to
the right and down, there are exactly 6 routes to the bottom right corner.
How many such routes are there through a 20×20 grid?
"""
from math import factorial


def lattice_paths(n):
def solution(n: int = 20) -> int:
"""
Returns the number of paths possible in a n x n grid starting at top left
corner going to bottom right corner and being able to move right and down
only.

bruno@bruno-laptop:~/git/Python/project_euler/problem_15$ python3 sol1.py 50
1.008913445455642e+29
bruno@bruno-laptop:~/git/Python/project_euler/problem_15$ python3 sol1.py 25
126410606437752.0
bruno@bruno-laptop:~/git/Python/project_euler/problem_15$ python3 sol1.py 23
8233430727600.0
bruno@bruno-laptop:~/git/Python/project_euler/problem_15$ python3 sol1.py 15
155117520.0
bruno@bruno-laptop:~/git/Python/project_euler/problem_15$ python3 sol1.py 1
2.0

>>> lattice_paths(25)
126410606437752
>>> lattice_paths(23)
8233430727600
>>> lattice_paths(20)
137846528820
>>> lattice_paths(15)
155117520
>>> lattice_paths(1)
2

Returns the number of paths possible in a n x n grid starting at top left
corner going to bottom right corner and being able to move right and down
only.
>>> solution(25)
126410606437752
>>> solution(23)
8233430727600
>>> solution(20)
137846528820
>>> solution(15)
155117520
>>> solution(1)
2
"""
n = 2 * n # middle entry of odd rows starting at row 3 is the solution for n = 1,
# 2, 3,...
Expand All @@ -46,10 +35,10 @@ def lattice_paths(n):
import sys

if len(sys.argv) == 1:
print(lattice_paths(20))
print(solution(20))
else:
try:
n = int(sys.argv[1])
print(lattice_paths(n))
print(solution(n))
except ValueError:
print("Invalid entry - please enter a number.")
8 changes: 5 additions & 3 deletions project_euler/problem_34/sol1.py
Original file line number Diff line number Diff line change
@@ -1,4 +1,6 @@
"""
Problem 34: https://projecteuler.net/problem=34

145 is a curious number, as 1! + 4! + 5! = 1 + 24 + 120 = 145.
Find the sum of all numbers which are equal to the sum of the factorial of their digits.
Note: As 1! = 1 and 2! = 2 are not sums they are not included.
Expand All @@ -18,17 +20,17 @@ def sum_of_digit_factorial(n: int) -> int:
return sum(factorial(int(char)) for char in str(n))


def compute() -> int:
def solution() -> int:
"""
Returns the sum of all numbers whose
sum of the factorials of all digits
add up to the number itself.
>>> compute()
>>> solution()
40730
"""
limit = 7 * factorial(9) + 1
return sum(i for i in range(3, limit) if sum_of_digit_factorial(i) == i)


if __name__ == "__main__":
print(f"{compute()} = ")
print(f"{solution()} = ")