Leetcode 81. 搜索旋转排序数组 II（DAY 186）

• • 原题题目
  • 代码实现（首刷自解）

class Solution {
public:
    bool helper(vector& nums,int left,int right,int target)
    {
        if(left == right)   return nums[left] == target;
        auto pos = lower_bound(nums.begin()+left,nums.begin()+right,target) - nums.begin();
        if(pos != right && nums[pos] == target) return true;

        int mid = (left + right)/2;  
        return helper(nums,left,mid,target) || helper(nums,left+1==right?mid+1:mid,right,target);
    }

    bool search(vector& nums, int target) {
        return helper(nums,0,nums.size()-1,target);
    }
};