From 488fbbef11879aa2133833da4f6c81c60b484d6e Mon Sep 17 00:00:00 2001 From: pathywang Date: Sun, 4 Oct 2026 05:40:40 +0100 Subject: [PATCH 1/2] improve prefix --- .../common_prefix/common_prefix.py | 20 ++++++++++++++----- 1 file changed, 15 insertions(+), 5 deletions(-) diff --git a/Sprint-2/improve_with_precomputing/common_prefix/common_prefix.py b/Sprint-2/improve_with_precomputing/common_prefix/common_prefix.py index f4839e7..718d7a7 100644 --- a/Sprint-2/improve_with_precomputing/common_prefix/common_prefix.py +++ b/Sprint-2/improve_with_precomputing/common_prefix/common_prefix.py @@ -7,18 +7,28 @@ def find_longest_common_prefix(strings: List[str]): In the event that an empty list, a list containing one string, or a list of strings with no common prefixes is passed, the empty string will be returned. """ + if len(strings) < 2: + return "" + + strings = sorted(strings) + longest = "" - for string_index, string in enumerate(strings): - for other_string in strings[string_index+1:]: - common = find_common_prefix(string, other_string) - if len(common) > len(longest): - longest = common + + for i in range(len(strings) - 1): + common = find_common_prefix(strings[i], strings[i + 1]) + + if len(common) > len(longest): + longest = common + return longest def find_common_prefix(left: str, right: str) -> str: min_length = min(len(left), len(right)) + for i in range(min_length): if left[i] != right[i]: return left[:i] + return left[:min_length] + From cda48d435c61e74b75aa371d788fd9a2174d9642 Mon Sep 17 00:00:00 2001 From: pathywang Date: Sun, 4 Oct 2026 05:42:37 +0100 Subject: [PATCH 2/2] improve count letters --- .../count_letters/count_letters.py | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/Sprint-2/improve_with_precomputing/count_letters/count_letters.py b/Sprint-2/improve_with_precomputing/count_letters/count_letters.py index 62c3ec0..54adcfd 100644 --- a/Sprint-2/improve_with_precomputing/count_letters/count_letters.py +++ b/Sprint-2/improve_with_precomputing/count_letters/count_letters.py @@ -2,13 +2,15 @@ def count_letters(s: str) -> int: """ count_letters returns the number of letters which only occur in upper case in the passed string. """ + letters = set(s) only_upper = set() - for letter in s: + for letter in letters: if is_upper_case(letter): - if letter.lower() not in s: + if letter.lower() not in letters: only_upper.add(letter) return len(only_upper) def is_upper_case(letter: str) -> bool: return letter == letter.upper() +