字节跳动面试真题-单调数组旋转二分查找

【字节跳动】2018暑期实习面试题

题目地址：

将一个原有序的数组移位后查找元素。
如[0,1,2,4,5,6,7]向右移动4位变成[4,5,6,7,0,1,2]

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

解题思路：

AC代码：

class Solution {
public:
    int search(vector& 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;
    }
};

顺便贴一个面试官问到的一个概率题