{"id":9757,"date":"2022-06-25T13:38:13","date_gmt":"2022-06-25T20:38:13","guid":{"rendered":"https:\/\/zxi.mytechroad.com\/blog\/?p=9757"},"modified":"2022-06-25T13:38:54","modified_gmt":"2022-06-25T20:38:54","slug":"leetcode-2315-count-asterisks","status":"publish","type":"post","link":"https:\/\/zxi.mytechroad.com\/blog\/string\/leetcode-2315-count-asterisks\/","title":{"rendered":"\u82b1\u82b1\u9171 LeetCode 2315. Count Asterisks"},"content":{"rendered":"\n

You are given a string s<\/code>, where every two<\/strong> consecutive vertical bars '|'<\/code> are grouped into a pair<\/strong>. In other words, the 1st<\/sup> and 2nd<\/sup> '|'<\/code> make a pair, the 3rd<\/sup> and 4th<\/sup> '|'<\/code> make a pair, and so forth.<\/p>\n\n\n\n

Return the number of <\/em>'*'<\/code> in <\/em>s<\/code>, excluding<\/strong> the <\/em>'*'<\/code> between each pair of <\/em>'|'<\/code>.<\/p>\n\n\n\n

Note<\/strong> that each '|'<\/code> will belong to exactly<\/strong> one pair.<\/p>\n\n\n\n

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

Input:<\/strong> s = \"l|*e*et|c**o|*de|\"\nOutput:<\/strong> 2\nExplanation:<\/strong> The considered characters are underlined: \"l|*e*et|c**o|*de|\".\nThe characters between the first and second '|' are excluded from the answer.\nAlso, the characters between the third and fourth '|' are excluded from the answer.\nThere are 2 asterisks considered. Therefore, we return 2.<\/pre>\n\n\n\n
Example 2:<\/strong><\/p>\n\n\n\n
Input:<\/strong> s = \"iamprogrammer\"\nOutput:<\/strong> 0\nExplanation:<\/strong> In this example, there are no asterisks in s. Therefore, we return 0.\n<\/pre>\n\n\n\n
Example 3:<\/strong><\/p>\n\n\n\n
Input:<\/strong> s = \"yo|uar|e**|b|e***au|tifu|l\"\nOutput:<\/strong> 5\nExplanation:<\/strong> The considered characters are underlined: \"yo|uar|e**|b|e***au|tifu|l\". There are 5 asterisks considered. Therefore, we return 5.<\/pre>\n\n\n\n
Constraints:<\/strong><\/p>\n\n\n\n
  • 1 <= s.length <= 1000<\/code><\/li>
  • s<\/code> consists of lowercase English letters, vertical bars '|'<\/code>, and asterisks '*'<\/code>.<\/li>
  • s<\/code> contains an even<\/strong> number of vertical bars '|'<\/code>.<\/li><\/ul>\n\n\n\n
    Solution: Counting<\/strong><\/h2>\n\n\n\n
    Count the number of bars so far, and only count ‘*’ when there are even number of bars on the left.<\/p>\n\n\n\n
    Time complexity: O(n)
    Space complexity: O(1)<\/p>\n\n\n\n
    \n
    C++<\/h2>\n
    \n\n
    \/\/ Author: Huahua\nclass Solution {\npublic:\n  int countAsterisks(string s) {\n    int bars = 0;\n    int ans = 0;    \n    for (char c : s) {\n      if (c == '*' && bars % 2 == 0)\n        ++ans;\n      if (c == '|') ++bars;      \n    }\n    return ans;\n  }\n};\n<\/pre>\n<\/div><\/div>\n","protected":false},"excerpt":{"rendered":"
    You are given a string s, where every two consecutive vertical bars ‘|’ are grouped into a pair. In other words, the 1st and 2nd ‘|’ make a pair, the 3rd and 4th ‘|’ make a pair,…<\/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":[222,4],"class_list":["post-9757","post","type-post","status-publish","format-standard","hentry","category-string","tag-easy","tag-string","entry","simple"],"_links":{"self":[{"href":"https:\/\/zxi.mytechroad.com\/blog\/wp-json\/wp\/v2\/posts\/9757","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=9757"}],"version-history":[{"count":2,"href":"https:\/\/zxi.mytechroad.com\/blog\/wp-json\/wp\/v2\/posts\/9757\/revisions"}],"predecessor-version":[{"id":9759,"href":"https:\/\/zxi.mytechroad.com\/blog\/wp-json\/wp\/v2\/posts\/9757\/revisions\/9759"}],"wp:attachment":[{"href":"https:\/\/zxi.mytechroad.com\/blog\/wp-json\/wp\/v2\/media?parent=9757"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/zxi.mytechroad.com\/blog\/wp-json\/wp\/v2\/categories?post=9757"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/zxi.mytechroad.com\/blog\/wp-json\/wp\/v2\/tags?post=9757"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}