The document describes different data structures and algorithms for representing and traversing linked data structures in memory. It discusses singly linked lists, doubly linked lists, trees, and graphs. It presents pseudocode for algorithms to traverse nodes by (1) recursively exploring all links, (2) using a stack to iteratively explore links in depth-first order, and (3) using a circular buffer and pointers to explore links in breadth-first order.

1. 2.3.5
twitter.com/jun0683

2. 0
a e
b c d f g
h
(a:(b,c,d),e:(f,g,:(h)))

3. RLINK :
DLINK :

4. A=(b,c,d) LIST=(A,a,(A,A))
b we might expectA=(c,d) ways to representthe same basic within
As
, ,These are many variations on List structures theme
a computer memory.
there
are usually
according to which binary trees are used to represent general forests of trees:
8ay, is used to point to the next element of a List, and another
LIST 3 -> b
one field
‘
field DLINI may be used to point to the first element of a sub-List. By a natural
extension of the memory representation described in Section 2.3.2, we would
represent the List (5) as follows:
b (atom) c e
-
-
g
(6)
-
-

5. a b (atom) c
-
-
9
(7)
-
- -
-

7. Memory &raight linkage Circular linkagc Doublc linkagc
……
location
……
INFO DLINK RLINK INFO DLINK
L…
m
RLINK INFO
h
[
o
om
RLINK
…… om
(t
b m ’6V W
b
o
mw
c
e A
m
c
t
O%
Om m
FU
( mm
{
h
” O mm
O
m
m (8)
-f -f -f
m m I m l m O%
g A g l % g l % om
-d m -d Lm a -d h m
J l % m
A o% { 0%
m A ka m h 1m m
- ’m h I
m h mm om mm
h
( m I %
J A 0m
w m { m l %
3 J
Here “LLINK" is used for a pointe1' to the left in a doubly linked 1'epresentation.

8. MIX
a) 1
S T REF RLINK
b)2
S T LLINK RLINK
INFO
s( ) :
t( ) : t=0 ,t=1
t>1
REF :
L,RLINK :
INFO : .( ,
, ..)

9. !
!

10. (reference counter)
( )
( )
( ?)
(garbage collection)

11. 1
2
( ) 0

12. A
NODE(1),NODE(2),...,NODE(M)
m
A1.
(
) 1
K=1 //K

13. A2.
K1=K+1 //K1 , K
if(NODE(K) != || NODE(K) != )
A3.
else
if(NODE(ALINK(K)) != )//
NODE(ALINK(K)) =
if(NODE(ALINK(K)) != )
K1 = min(K1,ALINK(K))
if(NODE(BLINK(K)) != )
K1 = min(K1,BLINK(K))

14. A3.
K=K1
if(k<=M)
A2
else

15. A
1 m
K m
K K1 m
K K1 m
K K1 m

17. B
STACK[1],.....
B1.
T
STACK[1].....,STACK[T]

18. B2.
/ T
/ STACK TOP ,
if(T=0)
end

19. B3.
//stack pop, K
K = STACK[T]
T=T-1

20. B4.
if(NODE(K) == )
B2
else
if(NODE(ALINK(K)) != )
NODE(ALINK(K)) =
T=T+1 //stack push
STACK[T] = ALINK(K)
if(NODE(BLINK(K)) != )
NODE(BLINK(K)) =
T=T+1
STACK[T] = BLINK(K)

21. B
v m
v m
9 5 v m
7 7 3 3 v m
1 1 1 1 1 v m

22. ..
..

23. C
H
STACK[0],....STACK[H-1]
X
T = (T+1)%H
STACK[T] = X
T=B
B = (B+1)%H
K1 = min(K1,STACK[B])

24. C1.
T = H-1 //TOP
B = H-1 //BOTTOM
K1 = M + 1 //
( % push)

25. C2.
if(T==B)
C5

26. C3
//stack pop
K = STACK[T]
T = (T-1)%H

27. C4
if(NODE(K) == )
C2
else
if(NODE(ALINK(K)) != )
NODE(ALINK(K)) =
ALINK(K) ( % push)
if(NODE(BLINK(K)) != )
NODE(BLINK(K)) =
BLINK(K) ( % push)
C2

28. C5
if( K1 > M ) // T=B
B = (B+1)%H
end K1 = min(K1,STACK[B])
else
if(NODE(K1) == || NODE(K1) != )
K1 = K1 + 1
C5
if (NODE(K1) == )
K = K1
K = K1 + 1
C4

29. C
v m
9 5
v m
v m
7 7 3 3 v m
v m
1 1 1 1 6 v m

30. D
A,B,C
ALINK BLINK S,T,REF,RLINK
s( ) :
t( ) : t=0 ,t=1
t>1
REF :
L,RLINK :
INFO : .( ,
, ..)

31. D1.
//TOP
TOP = NULL
P
if(S(P) == 0)
S(P)=1
REF(P) = TOP // TOP
TOP = P

32. D2.
if(TOP == NULL) //
end

33. D3
//TOP pop
P = TOP
TOP = REF(P)

34. D4.
P = RLINK(P)
if(P == NULL || T(P) == 0)//
D2
else
S(P) = 1
if(T(P) > 1) //
S(REF(P)) = 1
else
Q = REF(P)
if(Q != NULL && S(Q) == 0)
S(Q) = 1
REF(Q) = TOP
TOP = Q
D4

35. B TOP,Q
After Aftcl'
ALINK BLINK
E4. E5.
El. E2. Down Down E6. Up
Tnitinlìzc Mnrk ALINK I Mnrkcd BLINK I :hrked
already alrcady
Fig. 38. Flowchart f0 1' AIgorithm E.
E5. [Down BLINK.] Set Q • BLINK(P). If Q A and MARK(Q) = 0 , set
BLINK(P) • T, T • P, P • Q, and go to E2.
E6. [Up.] (This step undoes the link switching made in step E4 or E5; the
setting of ATOM (T) tells ALINK(T) or BLINK (T) is to be restored.)

36. E (1965 ...-_-)
MARK(1 )
ATOM( 1 )
0,1
ALINK
BLINK

37. E1.
T=NULL // T 2 NULL TOP P
P = P0 // P0

38. E2.
MARK(P) = 1 //

39. E3.
if(ATOM(P) == 1) // 0
E6

40. E4.
Q = ALINK(P)
if (Q != NULL && MARK(Q) == 0)
ATOM(P) = 1
ALINK(P) = T
T=P
p=Q
E2

41. E5
Q = BLINK(P)
if(Q != NULL && MARK(Q) == 0)
BLINK(P) = T
T=P
P=Q
E2

42. E6
if(T == NULL)
end
else
Q=T
if(ATOM(Q) == 1) if(ATOM(Q) == 0)
ATOM(Q) = 0 T = BLINK(Q)
T = ALINK(Q)
BLINK(Q) = P
ALINK(Q) = P
P=Q P=Q
E5 E6