how to make c++ looping patterns

I would like to produce pattern like this, please help my homework, because i'm newbie.

X X X
 XXX 
XXXXX
 XXX
X X X

XXXXX
X   X
X   X
X   X
XXXXX

X
XX
X X
X  X
XXXXX

    X
   XX
  X X
 X  X
XXXXX

please help me finish my homework