Algo(T,k)
ST=STX=STRET=LAST=NIL
CT=T
while(ct!=NIL || st!=NIL)do
	if(ct!=NIL)then
		ret=inf
		x=ct->k%2
		st=stx=push()
		ct=ct->sx
	else
		ct=top(st); x=top(stx);
		if(last!=ct->dx && ct->dx!=NIL)then
			y=val
			if(x=k%2)then
				ret=0
			else
				ret=y
			stret=push(stret,ret)
			ct=ct->dx
		else
			if(ct->dx=NIL)then
				y=val
				if(x=k%2)then
					ret=0
				else
					ret=y
				z=inf/nil
				ret=min(ret,z)+1
				+ uscita algoritmo
			else
				z=val
				ret=min(top(stret),z)+1
				+ uscita algoritmo
		return ret