iphone - View transition without using navigation controller? -

i want implement view transition without using navigation controller pushviewcontroller mechanism. so, created view hierarchy below. window superview , contains 3 subviews.

[window] - aviewcontroller - bviewcontroller - cviewcontroller  

if want go avewicontroller cviewcontroller, allocate aviewcontroller again this: [[aviewcontroller alloc] init].

then, after 4 circulations, got didreceivememorywarning , "program exited status value:0" messages. memory issue no memory leak. allocating viewcontroller on , on problem. have no idea how transit view in case.

if want hierarchy of uiviewcontrollers behave in uinavigationcontroller case should

a) show new viewcontroller call

//this code should implemented in viewcontrollera [self presentmodalviewcontroller:viewcontrollerb animated:yes] 

b) go 1 step calling

//this code should implemented in viewcontrollera [self dismissmodalviewcontrolleranimated:yes] 

notes: way tell viewcontrollera want close viewcontrollerb sending nsnotification. thing if want go viewcontrollerc viewcontrollera send notification viewcontrolera dissmismodalviewcontroller , recursively dismiss viewcontrollerc , viewcontrollerb you.

hope helps