DIY: Search in Rotated Sorted Array

Solve the interview question "Search in Rotated Sorted Array" in this lesson.

Problem statement

Search for a given number in a sorted array of unique elements that have been rotated an arbitrary number. Assume that an array is rotated at some point unknown to you beforehand (For example, [0,1,2,4,5,6,7] might become [4,5,6,7,0,1,2]).

Return the index if the number is found. Otherwise, return -1.


The input will be an array and an integer for which you have to find the index. The following is an example input:

arr = [4,5,6,7,0,1,2] 
key = 2


The output will be an integer representing the index of key in arr. The following is an example output:


Coding exercise

Implement the search_rotated(arr, key) function, where arr is the rotated array and key is the number you have to find in arr. The function returns the index of key if it exists. Otherwise, it returns -1.

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