There is definitely not same algorithm for all countries. I have been searching for sites ranked on google.com and other google.com.xx. Results are usually that Google.com prevents spam more or less successfully, and spam still works pretty much well on crappy google.com.xx
I had hard times watching websites ranked #1 on google.com.xx in medium competitive niche only with mass blog comments, web 2.0s and facebook shares, all backlinks PR 1 or lower.