702. Search in a Sorted Array of Unknown Size

Given an integer array sorted in ascending order, write a function to search target in nums .  If target exists, then return its index, otherwise return -1 . However, the array size is unknown to you . You may only access the array using an ArrayReader  interface, where  ArrayReader.get(k) returns the element of the array at index k  (0-indexed).

You may assume all integers in the array are less than  10000 , and if you access the array out of bounds, ArrayReader.get will return 2147483647 .

 

Example 1:

Input:

 
array

 = [-1,0,3,5,9,12], 
target

 = 9
Output:

 4
Explanation:

 9 exists in 
nums

 and its index is 4

Example 2:

Input:

 
array

 = [-1,0,3,5,9,12], 
target

 = 2
Output:

 -1
Explanation:

 2 does not exist in 
nums

 so return -1

 

Note:

1. You may assume that all elements in the array are unique.
2. The value of each element in the array will be in the range [-9999, 9999] .