ALGOIT(T,k,P)
ST=STP=STH1=LAST=NIL
CT=T
while(ct!=NIL || st!=NIL)do
	if(ct!=NIL)then
		ret=-1
		st=push(st,ct)
		stp=push(stp,cp)
		CP=CT
		ct=ct->sx
	else
		ct=top(st); cp=top(stp)
		if(last!=ct->dx && ct->dx!=NIL)then
			h1=val
			sth1=push(sth1,h1)
			ct=ct->dx
		else
			if(ct->dx=NIL)then
				h1=val
				h2=h1-1
				ret=h2+1
				if(ret > k ^ cp!=NIL)then
					if(ct=cp->dx)then
						cp->dx=cancellaroot(ct)
					else
						cp->sx=cancellaroot(ct)
					+uscita algoritmo
			else
				top(sth1); pop(sth1)
				h2=h1+val
				ret=h2+1
				if(ret > k ^ cp!=NIL)then
					if(ct=cp->dx)then
						cp->dx=cancellaroot(ct)
					else
						cp->sx=cancellaroot(ct)
					+uscita algoritmo
		return ret