Minimum Difference Element (medium)

Problem Statement

Given an array of numbers sorted in ascending order, find the element in the array that has the minimum difference with the given ‘key’.

Example 1:

Input: [4, 6, 10], key = 7
Output: 6
Explanation: The difference between the key '7' and '6' is minimum than any other number in the array 

Example 2:

Input: [4, 6, 10], key = 4
Output: 4

Example 3:

Input: [1, 3, 8, 10, 15], key = 12
Output: 10

Example 4:

Input: [4, 6, 10], key = 17
Output: 10

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