Put spaces between words starting with capital letters

You are given an array of characters which is basically a sentence. However, there is no space between different words and the first letter of every word is in uppercase. You need to print this sentence after following amendments: 

1. Put a single space between these words. 
2. Convert the uppercase letters to lowercase.

Examples:

Input : BruceWayneIsBatman
Output : bruce wayne is batman
Input : You
Output : you

We check if the current character is in uppercase then print " "(space) and convert it into lowercase. 

Implementation:

bruce wayne is batman

Time complexity:O(n)
Auxiliary Space: O(1)

Put spaces between words starting with capital letters using Regex.

bruce wayne is batman

Time complexity: O(n)
Auxiliary Space: O(n)