字節跳動面試真題-單調數組旋轉二分查找

【字節跳動】2018暑期實習面試題

題目地址：

將一個原有序的數組移位後查找元素。
如[0,1,2,4,5,6,7]向右移動4位變成[4,5,6,7,0,1,2]

https://leetcode.com/problems/search-in-rotated-sorted-array/

解題思路：

AC代碼：

class Solution {
public:
    int search(vector<int>& nums, int target) {
        int l = 0, r = nums.size() - 1, mid;
        
        while (l <= r) {
            mid = (l + r) >> 1;
            if (nums[mid] == target) {
                return mid;
            }
    
            if (nums[mid] >= nums[l]) {
                if (nums[l] <= target && target < nums[mid]) {
                    r = mid - 1;
                } else {
                    l = mid + 1;
                }
            } else {
                if (nums[mid] < target && target <= nums[r]) {
                    l = mid + 1;
                } else {
                    r = mid - 1;
                }
            }
        }
        return -1;
    }
};

順便貼一個面試官問到的一個概率題