Hi, here's your problem today. This problem was recently asked by LinkedIn:

Given a string, rearrange the string so that no character next to each other are the same. If no such arrangement is possible, then return None.

Example:
Input: abbccc
Output: cbcbca

<pre lang=py>
def rearrangeString(s):
  # Fill this in.

print rearrangeString('abbccc')
# cbcabc
</pre>