Median
Problem
Given a unsorted array with integers, find the median of it.
A median is the middle number of the array after it is sorted.
If there are even numbers in the array, return the N/2-th number after sorted.
Example
Given [4, 5, 1, 2, 3]
, return 3
Given [7, 9, 4, 5]
, return 5
Challenge
O(n)
time.