MAC OS X - photo library restore after format without backup

i've recently formatted my MAC OS X into snow leopard and unfortunately all the photos on Iphoto library on MAC was gone. i had no previous back ups for mac or even for my iphone 5S. i can't find the application anymore and apparently it doesnt support it even. i have had iphone since november 2013 so i am not sure if i could restore all the photos and videos i once had on my iphone or not.

excuse me for sounding illiterate.

any tip will help

thank you so much in advance.