{"id":8793,"date":"2021-11-26T17:51:32","date_gmt":"2021-11-27T01:51:32","guid":{"rendered":"https:\/\/zxi.mytechroad.com\/blog\/?p=8793"},"modified":"2021-11-26T17:51:58","modified_gmt":"2021-11-27T01:51:58","slug":"leetcode-33-search-in-rotated-sorted-array","status":"publish","type":"post","link":"https:\/\/zxi.mytechroad.com\/blog\/algorithms\/binary-search\/leetcode-33-search-in-rotated-sorted-array\/","title":{"rendered":"\u82b1\u82b1\u9171 LeetCode 33. Search in Rotated Sorted Array"},"content":{"rendered":"\n

There is an integer array nums<\/code> sorted in ascending order (with distinct<\/strong> values).<\/p>\n\n\n\n

Prior to being passed to your function, nums<\/code> is possibly rotated<\/strong> at an unknown pivot index k<\/code> (1 <= 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, [0,1,2,4,5,6,7]<\/code> might be rotated at pivot index 3<\/code> and become [4,5,6,7,0,1,2]<\/code>.<\/p>\n\n\n\n

Given the array nums<\/code> after<\/strong> the possible rotation and an integer target<\/code>, return the index of <\/em>target<\/code> if it is in <\/em>nums<\/code>, or <\/em>-1<\/code> if it is not in <\/em>nums<\/code>.<\/p>\n\n\n\n

You must write an algorithm with O(log n)<\/code> runtime complexity.<\/p>\n\n\n\n

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

Input:<\/strong> nums = [4,5,6,7,0,1,2], target = 0\nOutput:<\/strong> 4\n<\/pre>\n\n\n\n
Example 2:<\/strong><\/p>\n\n\n\n
Input:<\/strong> nums = [4,5,6,7,0,1,2], target = 3\nOutput:<\/strong> -1\n<\/pre>\n\n\n\n
Example 3:<\/strong><\/p>\n\n\n\n
Input:<\/strong> nums = [1], target = 0\nOutput:<\/strong> -1\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>
  • All values of nums<\/code> are unique<\/strong>.<\/li>
  • nums<\/code> is an ascending array that is possibly rotated.<\/li>
  • -104<\/sup> <= target <= 104<\/sup><\/code><\/li><\/ul>\n\n\n\n
    Solution: Binary Search<\/strong><\/h2>\n\n\n\n
    If the current range [l, r] is ordered, reduce to normal binary search. Otherwise, determine the range to search next by comparing target and nums[0].<\/p>\n\n\n\n
    Time complexity: O(logn)
    Space complexity: O(1)<\/p>\n\n\n\n
    \n
    C++<\/h2>\n
    \n\n
    \n\/\/ Author: Huahua\nclass Solution {\npublic:\n  int search(vector& nums, int target) {\n    int l = 0;\n    int r = nums.size();\n    while (l < r) {\n      int m = l + (r - l) \/ 2;\n      int x = (nums[m] < nums[0]) == (target < nums[0])\n              ? nums[m]\n              : target < nums[0] ? INT_MIN : INT_MAX;\n      if (x < target)\n        l = m + 1;\n      else if (x > target)\n        r = m;\n      else\n        return m;\n    }\n    return -1;\n  }\n};\n<\/pre>\n<\/div><\/div>\n","protected":false},"excerpt":{"rendered":"
    There is an integer array nums sorted in ascending order (with distinct values). Prior to being passed to your function, nums is possibly rotated at an unknown pivot index k (1 <= 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":[52,177,702],"class_list":["post-8793","post","type-post","status-publish","format-standard","hentry","category-binary-search","tag-binary-search","tag-medium","tag-rotated","entry","simple"],"_links":{"self":[{"href":"https:\/\/zxi.mytechroad.com\/blog\/wp-json\/wp\/v2\/posts\/8793","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=8793"}],"version-history":[{"count":2,"href":"https:\/\/zxi.mytechroad.com\/blog\/wp-json\/wp\/v2\/posts\/8793\/revisions"}],"predecessor-version":[{"id":8795,"href":"https:\/\/zxi.mytechroad.com\/blog\/wp-json\/wp\/v2\/posts\/8793\/revisions\/8795"}],"wp:attachment":[{"href":"https:\/\/zxi.mytechroad.com\/blog\/wp-json\/wp\/v2\/media?parent=8793"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/zxi.mytechroad.com\/blog\/wp-json\/wp\/v2\/categories?post=8793"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/zxi.mytechroad.com\/blog\/wp-json\/wp\/v2\/tags?post=8793"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}