#include #include /** * 81. Search in Rotated Sorted Array II * 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) such that the resulting array is [nums[k], nums[k+1], ..., nums[n-1], nums[0], nums[1], ..., nums[k-1]] (0-indexed). For example, [0,1,2,4,4,4,5,6,6,7] might be rotated at pivot index 5 and become [4,5,6,6,7,0,1,2,4,4]. * Given the array nums after the rotation and an integer target, return true if target is in nums, or false if it is not in nums. * You must decrease the overall operation steps as much as possible. * * Analysis: * class Solution has a complexity of O(n). * class SolutionBinary has O(n + 2 * log(n)) -> O(n). * * But which is faster? I sorely have no idea. */ class Solution { public: static bool search(const std::vector& nums, int target) { return std::any_of(nums.begin(), nums.end(), [&](int x){ return x == target; }); } }; class SolutionBinary { public: static bool search(const std::vector& nums, int target) { auto it = std::next(nums.begin()); for (; it != nums.end(); ++it) if (*it < *std::prev(it)) break; if (it == nums.end()) return std::binary_search(nums.begin(), nums.end(), target); return std::binary_search(nums.begin(), it, target) || std::binary_search(it, nums.end(), target); } };