{"id":8937,"date":"2021-11-29T00:47:01","date_gmt":"2021-11-29T08:47:01","guid":{"rendered":"https:\/\/zxi.mytechroad.com\/blog\/?p=8937"},"modified":"2021-11-29T00:48:19","modified_gmt":"2021-11-29T08:48:19","slug":"leetcode-81-search-in-rotated-sorted-array-ii","status":"publish","type":"post","link":"https:\/\/zxi.mytechroad.com\/blog\/algorithms\/binary-search\/leetcode-81-search-in-rotated-sorted-array-ii\/","title":{"rendered":"\u82b1\u82b1\u9171 LeetCode 81. Search in Rotated Sorted Array II"},"content":{"rendered":"\n

There is an integer array nums<\/code> sorted in non-decreasing order (not necessarily with distinct<\/strong> values).<\/p>\n\n\n\n

Before being passed to your function, nums<\/code> is rotated<\/strong> at an unknown pivot index k<\/code> (0 <= k < nums.length<\/code>) such that the resulting array is [nums[k], nums[k+1], ..., nums[n-1], nums[0], nums[1], ..., nums[k-1]]<\/code> (0-indexed<\/strong>). For example, [0,1,2,4,4,4,5,6,6,7]<\/code> might be rotated at pivot index 5<\/code> and become [4,5,6,6,7,0,1,2,4,4]<\/code>.<\/p>\n\n\n\n

Given the array nums<\/code> after<\/strong> the rotation and an integer target<\/code>, return true<\/code> if <\/em>target<\/code> is in <\/em>nums<\/code>, or <\/em>false<\/code> if it is not in <\/em>nums<\/code>.<\/em><\/p>\n\n\n\n

You must decrease the overall operation steps as much as possible.<\/p>\n\n\n\n

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

Input:<\/strong> nums = [2,5,6,0,0,1,2], target = 0\nOutput:<\/strong> true\n<\/pre>\n\n\n\n
Example 2:<\/strong><\/p>\n\n\n\n
Input:<\/strong> nums = [2,5,6,0,0,1,2], target = 3\nOutput:<\/strong> false\n<\/pre>\n\n\n\n
Constraints:<\/strong><\/p>\n\n\n\n
  • 1 <= nums.length <= 5000<\/code><\/li>
  • -104<\/sup> <= nums[i] <= 104<\/sup><\/code><\/li>
  • nums<\/code> is guaranteed to be rotated at some pivot.<\/li>
  • -104<\/sup> <= target <= 104<\/sup><\/code><\/li><\/ul>\n\n\n\n
    Solution: Binary search or divide and conquer<\/strong><\/h2>\n\n\n\n
    If current range is ordered, use binary search, Otherwise, divide and conquer.<\/p>\n\n\n\n
    Time complexity: O(logn) best, O(n) worst
    Space complexity: O(logn)<\/p>\n\n\n\n
    \n
    C++<\/h2>\n
    \n\n
    \n\/\/ Author: Huahua\nclass Solution {\npublic:\n  bool search(vector& A, int target) {\n    return search(A, 0, A.size() - 1, target);\n  }\nprivate:\n  bool search(vector& A, int l, int r, int target) {\n    if (l > r) return 0;\n    if (l == r) return target == A[l];\n\n    int mid = l + (r - l) \/ 2;\n\n    if (A[l] < A[mid] && A[mid] < A[r])\n      return (target <= A[mid]) ? search(A, l, mid, target) : search(A, mid + 1, r, target);\n    else\n      return search(A, l, mid, target) || search(A, mid + 1, r, target);\n  }\n};\n<\/pre>\n<\/div><\/div>\n","protected":false},"excerpt":{"rendered":"
    There is an integer array nums sorted in non-decreasing order (not necessarily with distinct values). Before being passed to your function, nums is rotated at an unknown pivot index k (0 <= k < nums.length)…<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[149],"tags":[20,52,177,702],"class_list":["post-8937","post","type-post","status-publish","format-standard","hentry","category-binary-search","tag-array","tag-binary-search","tag-medium","tag-rotated","entry","simple"],"_links":{"self":[{"href":"https:\/\/zxi.mytechroad.com\/blog\/wp-json\/wp\/v2\/posts\/8937","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=8937"}],"version-history":[{"count":2,"href":"https:\/\/zxi.mytechroad.com\/blog\/wp-json\/wp\/v2\/posts\/8937\/revisions"}],"predecessor-version":[{"id":8939,"href":"https:\/\/zxi.mytechroad.com\/blog\/wp-json\/wp\/v2\/posts\/8937\/revisions\/8939"}],"wp:attachment":[{"href":"https:\/\/zxi.mytechroad.com\/blog\/wp-json\/wp\/v2\/media?parent=8937"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/zxi.mytechroad.com\/blog\/wp-json\/wp\/v2\/categories?post=8937"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/zxi.mytechroad.com\/blog\/wp-json\/wp\/v2\/tags?post=8937"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}