{"id":8650,"date":"2021-11-01T18:35:52","date_gmt":"2021-11-02T01:35:52","guid":{"rendered":"https:\/\/zxi.mytechroad.com\/blog\/?p=8650"},"modified":"2021-11-01T18:36:18","modified_gmt":"2021-11-02T01:36:18","slug":"leetcode-2053-kth-distinct-string-in-an-array","status":"publish","type":"post","link":"https:\/\/zxi.mytechroad.com\/blog\/hashtable\/leetcode-2053-kth-distinct-string-in-an-array\/","title":{"rendered":"\u82b1\u82b1\u9171 LeetCode 2053. Kth Distinct String in an Array"},"content":{"rendered":"\n

A distinct string<\/strong> is a string that is present only once<\/strong> in an array.<\/p>\n\n\n\n

Given an array of strings arr<\/code>, and an integer k<\/code>, return the <\/em>kth<\/sup><\/code> distinct string<\/strong> present in <\/em>arr<\/code>. If there are fewer<\/strong> than k<\/code> distinct strings, return an empty string <\/strong><\/em>\"\"<\/code>.<\/p>\n\n\n\n

Note that the strings are considered in the order in which they appear<\/strong> in the array.<\/p>\n\n\n\n

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

Input:<\/strong> arr = [\"d\",\"b\",\"c\",\"b\",\"c\",\"a\"], k = 2\nOutput:<\/strong> \"a\"\nExplanation:<\/strong>\nThe only distinct strings in arr are \"d\" and \"a\".\n\"d\" appears 1st<\/sup>, so it is the 1st<\/sup> distinct string.\n\"a\" appears 2nd<\/sup>, so it is the 2nd<\/sup> distinct string.\nSince k == 2, \"a\" is returned. \n<\/pre>\n\n\n\n
Example 2:<\/strong><\/p>\n\n\n\n
Input:<\/strong> arr = [\"aaa\",\"aa\",\"a\"], k = 1\nOutput:<\/strong> \"aaa\"\nExplanation:<\/strong>\nAll strings in arr are distinct, so the 1st<\/sup> string \"aaa\" is returned.\n<\/pre>\n\n\n\n
Example 3:<\/strong><\/p>\n\n\n\n
Input:<\/strong> arr = [\"a\",\"b\",\"a\"], k = 3\nOutput:<\/strong> \"\"\nExplanation:<\/strong>\nThe only distinct string is \"b\". Since there are fewer than 3 distinct strings, we return an empty string \"\".\n<\/pre>\n\n\n\n
Constraints:<\/strong><\/p>\n\n\n\n
  • 1 <= k <= arr.length <= 1000<\/code><\/li>
  • 1 <= arr[i].length <= 5<\/code><\/li>
  • arr[i]<\/code> consists of lowercase English letters.<\/li><\/ul>\n\n\n\n
    Solution: Hashtable<\/strong><\/h2>\n\n\n\n
    Time complexity: O(n)
    Space complexity: O(n)<\/p>\n\n\n\n
    \n
    C++<\/h2>\n
    \n\n
    \n\/\/ Author: Huahua\nclass Solution {\npublic:\n  string kthDistinct(vector& arr, int k) {\n    unordered_map m;\n    for (const string& s : arr)\n      ++m[s];    \n    for (const string& s : arr)\n      if (m[s] == 1 && --k == 0) return s;    \n    return \"\";\n  }\n};\n<\/pre>\n<\/div><\/div>\n","protected":false},"excerpt":{"rendered":"
    A distinct string is a string that is present only once in an array. Given an array of strings arr, and an integer k, return the kth distinct string present in arr. If there are fewer than k distinct strings,…<\/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":[20,222,82,4],"class_list":["post-8650","post","type-post","status-publish","format-standard","hentry","category-hashtable","tag-array","tag-easy","tag-hashtable","tag-string","entry","simple"],"_links":{"self":[{"href":"https:\/\/zxi.mytechroad.com\/blog\/wp-json\/wp\/v2\/posts\/8650","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=8650"}],"version-history":[{"count":2,"href":"https:\/\/zxi.mytechroad.com\/blog\/wp-json\/wp\/v2\/posts\/8650\/revisions"}],"predecessor-version":[{"id":8652,"href":"https:\/\/zxi.mytechroad.com\/blog\/wp-json\/wp\/v2\/posts\/8650\/revisions\/8652"}],"wp:attachment":[{"href":"https:\/\/zxi.mytechroad.com\/blog\/wp-json\/wp\/v2\/media?parent=8650"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/zxi.mytechroad.com\/blog\/wp-json\/wp\/v2\/categories?post=8650"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/zxi.mytechroad.com\/blog\/wp-json\/wp\/v2\/tags?post=8650"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}