{"id":9506,"date":"2022-02-26T21:10:38","date_gmt":"2022-02-27T05:10:38","guid":{"rendered":"https:\/\/zxi.mytechroad.com\/blog\/?p=9506"},"modified":"2022-02-26T21:11:07","modified_gmt":"2022-02-27T05:11:07","slug":"leetcode-2185-counting-words-with-a-given-prefix","status":"publish","type":"post","link":"https:\/\/zxi.mytechroad.com\/blog\/string\/leetcode-2185-counting-words-with-a-given-prefix\/","title":{"rendered":"\u82b1\u82b1\u9171 LeetCode 2185. Counting Words With a Given Prefix"},"content":{"rendered":"\n

You are given an array of strings words<\/code> and a string pref<\/code>.<\/p>\n\n\n\n

Return the number of strings in <\/em>words<\/code> that contain <\/em>pref<\/code> as a prefix<\/strong><\/em>.<\/p>\n\n\n\n

A prefix<\/strong> of a string s<\/code> is any leading contiguous substring of s<\/code>.<\/p>\n\n\n\n

Example 1:<\/strong><\/p>\n\n\n\n

Input:<\/strong> words = [\"pay\",\"at<\/u><\/strong>tention\",\"practice\",\"at<\/strong>tend\"], pref <\/code>= \"at\"\nOutput:<\/strong> 2\nExplanation:<\/strong> The 2 strings that contain \"at\" as a prefix are: \"at<\/strong>tention\" and \"at<\/strong>tend\".\n<\/pre>\n\n\n\n
Example 2:<\/strong><\/p>\n\n\n\n
Input:<\/strong> words = [\"leetcode\",\"win\",\"loops\",\"success\"], pref <\/code>= \"code\"\nOutput:<\/strong> 0\nExplanation:<\/strong> There are no strings that contain \"code\" as a prefix.\n<\/pre>\n\n\n\n
Constraints:<\/strong><\/p>\n\n\n\n
  • 1 <= words.length <= 100<\/code><\/li>
  • 1 <= words[i].length, pref.length <= 100<\/code><\/li>
  • words[i]<\/code> and pref<\/code> consist of lowercase English letters.<\/li><\/ul>\n\n\n\n
    Solution: Straight forward <\/strong><\/h2>\n\n\n\n
    We can use std::count_if and std::string::find.<\/p>\n\n\n\n
    Time complexity: O(n*l)
    Space complexity: O(1)<\/p>\n\n\n\n
    \n
    C++<\/h2>\n
    \n\n
    \n\/\/ Author: Huahua\nclass Solution {\npublic:\n  int prefixCount(vector& words, string pref) {\n    return count_if(begin(words), end(words), [&](const string& w) {\n      return w.find(pref) == 0;\n    });\n  }\n};\n<\/pre>\n<\/div><\/div>\n","protected":false},"excerpt":{"rendered":"
    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. Example…<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[47],"tags":[756,222,595,4],"class_list":["post-9506","post","type-post","status-publish","format-standard","hentry","category-string","tag-count_if","tag-easy","tag-find","tag-string","entry","simple"],"_links":{"self":[{"href":"https:\/\/zxi.mytechroad.com\/blog\/wp-json\/wp\/v2\/posts\/9506","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/zxi.mytechroad.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/zxi.mytechroad.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/zxi.mytechroad.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/zxi.mytechroad.com\/blog\/wp-json\/wp\/v2\/comments?post=9506"}],"version-history":[{"count":2,"href":"https:\/\/zxi.mytechroad.com\/blog\/wp-json\/wp\/v2\/posts\/9506\/revisions"}],"predecessor-version":[{"id":9508,"href":"https:\/\/zxi.mytechroad.com\/blog\/wp-json\/wp\/v2\/posts\/9506\/revisions\/9508"}],"wp:attachment":[{"href":"https:\/\/zxi.mytechroad.com\/blog\/wp-json\/wp\/v2\/media?parent=9506"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/zxi.mytechroad.com\/blog\/wp-json\/wp\/v2\/categories?post=9506"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/zxi.mytechroad.com\/blog\/wp-json\/wp\/v2\/tags?post=9506"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}