2185. Counting Words With a Given Prefix
Problem
You are given an array of strings words and a string pref.
Return the number of strings in words that contain pref as a prefix.
A prefix of a string s is any leading contiguous substring of s.
https://leetcode.com/problems/counting-words-with-a-given-prefix/
Example 1:
Input:
words = ["pay","attention","practice","attend"], pref = "at"
Output:2
Explanation: The 2 strings that contain"at"as a prefix are:"attention"and"attend".
Example 2:
Input:
words = ["leetcode","win","loops","success"], pref = "code"
Output:0
Explanation: There are no strings that contain"code"as a prefix.
Constraints:
1 <= words.length <= 1001 <= words[i].length, pref.length <= 100words[i]andprefconsist of lowercase English letters.
Test Cases
class Solution:
def prefixCount(self, words: List[str], pref: str) -> int:solution_test.py下载完整源码
import pytest
from solution import Solution
@pytest.mark.parametrize('words, pref, expected', [
(["pay","attention","practice","attend"], "at", 2),
(["leetcode","win","loops","success"], "code", 0),
])
@pytest.mark.parametrize('sol', [Solution()])
def test_solution(sol, words, pref, expected):
assert sol.prefixCount(words, pref) == expected
Thoughts
Code
solution.py下载完整源码
class Solution:
def prefixCount(self, words: list[str], pref: str) -> int:
return sum(1 for word in words if word.startswith(pref))
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