Trace the function ct2() and describe its action.
template
int ct2 (tnode *t)
{
int ctleft, ctright, ct;
if (t == null)
ct = 0; else
{
ctleft= ct2(t-> left);
ctright= ct2(t-> right);
ct = ctleft + ctright +
((t-> left ! = null & & t-> right ! = null) ? 1 : 0);
}
return ct;
}