Intro (Bruno Mars):
A                        C#m
I wanna be a billionaire so fucking bad
F#m                           E
Buy all of the things I never had
A                          C#m
I wanna be on the cover of Forbes magazine
F#m                           E
Smiling next to Oprah and the Queen
    F#m          E            A
Oh, every time I close my eyes
  F#m            E             A
I see my name in shining lights
F#m         E          A
A different city every night
C#m  F#m  Bm
Oh   I-I  swear,
                    C#m
The world better prepare
                         A
For when I'm a billionaire

Verse 1 and 2 follow the same progression as the beginning A - C#m - F#m - E

3rd chorus is normal, but the 2nd chorus starts at "Oh every time I close my eyes..." 
has a little extra at the end of it where it just repeats billionaire. That little part is 
A - E

The end is just A - C#m

If you listen to the song, you'll get the idea of the strumming. Its reggae-esque and a 
catchy song. Hope this helps everyone!