From 0f75804451cbb0b1ada4f2896131d90b88dfc4bc Mon Sep 17 00:00:00 2001
From: Manpreet Singh <63737630+ManpreetSingh2004@users.noreply.github.com>
Date: Sat, 14 Oct 2023 21:21:54 +0530
Subject: [PATCH 1/3] Performance: 80% faster Project Euler145
---
project_euler/problem_145/sol1.py | 7 +++++++
1 file changed, 7 insertions(+)
diff --git a/project_euler/problem_145/sol1.py b/project_euler/problem_145/sol1.py
index e9fc1a199161..c69a1440e543 100644
--- a/project_euler/problem_145/sol1.py
+++ b/project_euler/problem_145/sol1.py
@@ -30,6 +30,10 @@ def reversible_numbers(
>>> reversible_numbers(3, 0, [0] * 3, 3)
100
"""
+ # There exist no reversible 1, 5, 9, 13 (ie. 4k+1) digit numbers
+ if (length - 1) % 4 == 0:
+ return 0
+
if remaining_length == 0:
if digits[0] == 0 or digits[-1] == 0:
return 0
@@ -94,3 +98,6 @@ def solution(max_power: int = 9) -> int:
if __name__ == "__main__":
print(f"{solution() = }")
+
+ # for i in range(1, 15):
+ # print(f"{i}. {reversible_numbers(i, 0, [0]*i, i)}")
From bf77690f36f6fe6b7a5d01dd909d35173ea7a4b8 Mon Sep 17 00:00:00 2001
From: Manpreet Singh <63737630+ManpreetSingh2004@users.noreply.github.com>
Date: Sat, 14 Oct 2023 22:32:31 +0530
Subject: [PATCH 2/3] Added timeit benchmark
---
project_euler/problem_145/sol1.py | 71 ++++++++++++++++++++++++++-----
1 file changed, 60 insertions(+), 11 deletions(-)
diff --git a/project_euler/problem_145/sol1.py b/project_euler/problem_145/sol1.py
index c69a1440e543..7f761d834973 100644
--- a/project_euler/problem_145/sol1.py
+++ b/project_euler/problem_145/sol1.py
@@ -17,23 +17,19 @@
ODD_DIGITS = [1, 3, 5, 7, 9]
-def reversible_numbers(
+def slow_reversible_numbers(
remaining_length: int, remainder: int, digits: list[int], length: int
) -> int:
"""
Count the number of reversible numbers of given length.
Iterate over possible digits considering parity of current sum remainder.
- >>> reversible_numbers(1, 0, [0], 1)
+ >>> slow_reversible_numbers(1, 0, [0], 1)
0
- >>> reversible_numbers(2, 0, [0] * 2, 2)
+ >>> slow_reversible_numbers(2, 0, [0] * 2, 2)
20
- >>> reversible_numbers(3, 0, [0] * 3, 3)
+ >>> slow_reversible_numbers(3, 0, [0] * 3, 3)
100
"""
- # There exist no reversible 1, 5, 9, 13 (ie. 4k+1) digit numbers
- if (length - 1) % 4 == 0:
- return 0
-
if remaining_length == 0:
if digits[0] == 0 or digits[-1] == 0:
return 0
@@ -55,7 +51,7 @@ def reversible_numbers(
result = 0
for digit in range(10):
digits[length // 2] = digit
- result += reversible_numbers(
+ result += slow_reversible_numbers(
0, (remainder + 2 * digit) // 10, digits, length
)
return result
@@ -71,7 +67,7 @@ def reversible_numbers(
for digit2 in other_parity_digits:
digits[(length - remaining_length) // 2] = digit2
- result += reversible_numbers(
+ result += slow_reversible_numbers(
remaining_length - 2,
(remainder + digit1 + digit2) // 10,
digits,
@@ -80,6 +76,42 @@ def reversible_numbers(
return result
+def slow_solution(max_power: int = 9) -> int:
+ """
+ To evaluate the solution, use solution()
+ >>> solution(3)
+ 120
+ >>> solution(6)
+ 18720
+ >>> solution(7)
+ 68720
+ """
+ result = 0
+ for length in range(1, max_power + 1):
+ result += slow_reversible_numbers(length, 0, [0] * length, length)
+ return result
+
+
+def reversible_numbers(
+ remaining_length: int, remainder: int, digits: list[int], length: int
+) -> int:
+ """
+ Count the number of reversible numbers of given length.
+ Iterate over possible digits considering parity of current sum remainder.
+ >>> reversible_numbers(1, 0, [0], 1)
+ 0
+ >>> reversible_numbers(2, 0, [0] * 2, 2)
+ 20
+ >>> reversible_numbers(3, 0, [0] * 3, 3)
+ 100
+ """
+ # There exist no reversible 1, 5, 9, 13 (ie. 4k+1) digit numbers
+ if (length - 1) % 4 == 0:
+ return 0
+
+ return slow_reversible_numbers(length, 0, [0] * length, length)
+
+
def solution(max_power: int = 9) -> int:
"""
To evaluate the solution, use solution()
@@ -96,8 +128,25 @@ def solution(max_power: int = 9) -> int:
return result
+def benchmark() -> None:
+ """
+ Benchmarks
+ """
+ # Running performance benchmarks...
+ # slow_solution : 292.9300301000003
+ # solution : 54.90970860000016
+
+ from timeit import timeit
+
+ print("Running performance benchmarks...")
+
+ print(f"slow_solution : {timeit('slow_solution()', globals=globals(), number=10)}")
+ print(f"solution : {timeit('solution()', globals=globals(), number=10)}")
+
+
if __name__ == "__main__":
- print(f"{solution() = }")
+ print(f"Solution : {solution()}")
+ benchmark()
# for i in range(1, 15):
# print(f"{i}. {reversible_numbers(i, 0, [0]*i, i)}")
From c1dfb5a26f3c4afceef3b76568d15b6e502b078d Mon Sep 17 00:00:00 2001
From: Manpreet Singh <63737630+ManpreetSingh2004@users.noreply.github.com>
Date: Sat, 14 Oct 2023 22:44:24 +0530
Subject: [PATCH 3/3] >>> slow_solution() doctest
---
project_euler/problem_145/sol1.py | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/project_euler/problem_145/sol1.py b/project_euler/problem_145/sol1.py
index 7f761d834973..71b851178fdb 100644
--- a/project_euler/problem_145/sol1.py
+++ b/project_euler/problem_145/sol1.py
@@ -79,11 +79,11 @@ def slow_reversible_numbers(
def slow_solution(max_power: int = 9) -> int:
"""
To evaluate the solution, use solution()
- >>> solution(3)
+ >>> slow_solution(3)
120
- >>> solution(6)
+ >>> slow_solution(6)
18720
- >>> solution(7)
+ >>> slow_solution(7)
68720
"""
result = 0