{"id":9821,"date":"2022-09-17T08:32:25","date_gmt":"2022-09-17T15:32:25","guid":{"rendered":"https:\/\/zxi.mytechroad.com\/blog\/?p=9821"},"modified":"2022-09-17T08:32:49","modified_gmt":"2022-09-17T15:32:49","slug":"leetcode-2399-check-distances-between-same-letters","status":"publish","type":"post","link":"https:\/\/zxi.mytechroad.com\/blog\/hashtable\/leetcode-2399-check-distances-between-same-letters\/","title":{"rendered":"\u82b1\u82b1\u9171 LeetCode 2399.\u00a0Check Distances Between Same Letters"},"content":{"rendered":"\n

You are given a 0-indexed<\/strong> string s<\/code> consisting of only lowercase English letters, where each letter in s<\/code> appears exactly<\/strong> twice<\/strong>. You are also given a 0-indexed<\/strong> integer array distance<\/code> of length 26<\/code>.<\/p>\n\n\n\n

Each letter in the alphabet is numbered from 0<\/code> to 25<\/code> (i.e. 'a' -> 0<\/code>, 'b' -> 1<\/code>, 'c' -> 2<\/code>, … , 'z' -> 25<\/code>).<\/p>\n\n\n\n

In a well-spaced<\/strong> string, the number of letters between the two occurrences of the ith<\/sup><\/code> letter is distance[i]<\/code>. If the ith<\/sup><\/code> letter does not appear in s<\/code>, then distance[i]<\/code> can be ignored<\/strong>.<\/p>\n\n\n\n

Return true<\/code> if <\/em>s<\/code> is a well-spaced<\/strong> string, otherwise return <\/em>false<\/code>.<\/p>\n\n\n\n

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

Input:<\/strong> s = \"abaccb\", distance = [1,3,0,5,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0]\nOutput:<\/strong> true\nExplanation:<\/strong>\n- 'a' appears at indices 0 and 2 so it satisfies distance[0] = 1.\n- 'b' appears at indices 1 and 5 so it satisfies distance[1] = 3.\n- 'c' appears at indices 3 and 4 so it satisfies distance[2] = 0.\nNote that distance[3] = 5, but since 'd' does not appear in s, it can be ignored.\nReturn true because s is a well-spaced string.\n<\/pre>\n\n\n\n
Example 2:<\/strong><\/p>\n\n\n\n
Input:<\/strong> s = \"aa\", distance = [1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0]\nOutput:<\/strong> false\nExplanation:<\/strong>\n- 'a' appears at indices 0 and 1 so there are zero letters between them.\nBecause distance[0] = 1, s is not a well-spaced string.\n<\/pre>\n\n\n\n
Constraints:<\/strong><\/p>\n\n\n\n
  • 2 <= s.length <= 52<\/code><\/li>
  • s<\/code> consists only of lowercase English letters.<\/li>
  • Each letter appears in s<\/code> exactly twice.<\/li>
  • distance.length == 26<\/code><\/li>
  • 0 <= distance[i] <= 50<\/code><\/li><\/ul>\n\n\n\n
    Solution: Hashtable<\/strong><\/h2>\n\n\n\n
    Use a hastable to store the index of first occurrence of each letter.<\/p>\n\n\n\n
    Time complexity: O(n)
    Space complexity: O(26)<\/p>\n\n\n\n
    \n
    C++<\/h2>\n
    \n\n
    \n\/\/ Author: Huahua\nclass Solution {\npublic:\n  bool checkDistances(string s, vector& distance) {\n    vector m(26, -1);\n    for (int i = 0; i < s.length(); ++i) {\n      int c = s[i] - 'a';\n      if (m[c] >= 0 && i - m[c] - 1 != distance[c]) return false;\n      m[c] = i;\n    }\n    return true;\n  }\n};\n<\/pre>\n<\/div><\/div>\n","protected":false},"excerpt":{"rendered":"
    You are given a 0-indexed string s consisting of only lowercase English letters, where each letter in s appears exactly twice. You are also given a 0-indexed integer array distance of length 26. Each letter in the alphabet…<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[70],"tags":[222,82,4],"class_list":["post-9821","post","type-post","status-publish","format-standard","hentry","category-hashtable","tag-easy","tag-hashtable","tag-string","entry","simple"],"_links":{"self":[{"href":"https:\/\/zxi.mytechroad.com\/blog\/wp-json\/wp\/v2\/posts\/9821","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=9821"}],"version-history":[{"count":2,"href":"https:\/\/zxi.mytechroad.com\/blog\/wp-json\/wp\/v2\/posts\/9821\/revisions"}],"predecessor-version":[{"id":9823,"href":"https:\/\/zxi.mytechroad.com\/blog\/wp-json\/wp\/v2\/posts\/9821\/revisions\/9823"}],"wp:attachment":[{"href":"https:\/\/zxi.mytechroad.com\/blog\/wp-json\/wp\/v2\/media?parent=9821"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/zxi.mytechroad.com\/blog\/wp-json\/wp\/v2\/categories?post=9821"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/zxi.mytechroad.com\/blog\/wp-json\/wp\/v2\/tags?post=9821"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}