Upload
tratgiakiet2008
View
219
Download
0
Embed Size (px)
Citation preview
8/14/2019 cc Thut Gii t mu
1/18
T MU TH
ThS. Vnh By
Khoa Cn n h Thn tin
i hc K thut Cng ngh Tp. HCM
1
8/14/2019 cc Thut Gii t mu
2/18
BI TON
Cho m t th m n nh. uan h ia nh i v nh
j, k hiu Qhij, l 1 nu nh i c ni vi nh j v 0 nungc li.
to n t ra m t n o t m u t sao c o
khng tn ti hai nh c quan h vi nhau c tchung mt mu vi s mu cn t l t nht?
Ths.V
nh
By
2
8/14/2019 cc Thut Gii t mu
3/18
V D
a
a
d
b c
e
b c
de
Ths.V
p
h
p
h
nh
By
T 3 mu t nht cha?
3
8/14/2019 cc Thut Gii t mu
4/18
THUT GII T MU TI UBc 1: [T mu] T mu i (i bt u xt t 1) cho nh c bc
ln nht.
Bc 2: [H bc & cm t]2.1. Bc ca nh c t mu i th bc:=0.
Ths.V
2.2. Bc ca n c quan v n c t mu t bc:= bc 1.
nh
By
. . .
Bc 3: Lp li bc 1 cho n khi tt c cc nh u c tmu.
4
8/14/2019 cc Thut Gii t mu
5/18
MINH HAb c
e
a
h
b c
aa
b c
d
h
d
h
5
Ths. Vnh By
8/14/2019 cc Thut Gii t mu
6/18
V D 2
Mt cng ty c 8 i pht thanh A, B, C, D, E, F, G, H c khongcch (km) c cho trong ma trn sau:
A B C D E F G H
A 0 100 50 30 200 150 40 120
B 0 30 80 120 50 200 150
Ths.V
C 0 120 100 30 80 50
D 0 50 120 150 30
nh
By
F 0 180 150
G 0 50
Do yu cu k thut nn cc i c khong cch 100km khng
H 0
.sng sao cho s trm cn lp lnh nht.
6
8/14/2019 cc Thut Gii t mu
7/18
GII UYT
A B C D E F G H
A 0 100 50 30 200 150 40 120
B 0 30 80 120 50 200 150
D 0 50 120 150 30
E 0 200 120 120
F 0 180 150.
a) nh: gm cc i pht thanhb) Cung: ni gia 2 i c khong cch 100km.
G 0 50
H 0
Ta c ma trn quan h (hay th quan h nh sau):A B C D E F G H Bc
A 0 1 0 0 1 1 0 1 4
Ths.V
n
B 1 0 0 0 1 0 1 1 4
C 0 0 0 1 1 0 0 0 2
h
By
E 1 1 1 0 0 1 1 1 6
F 1 0 0 1 1 0 1 1 57G 0 1 0 1 1 1 0 0 4
H 1 1 0 0 1 1 0 0 4
8/14/2019 cc Thut Gii t mu
8/18
GII QUYT
(TT
)
A B C D E F G H
A 0 1 0 0 1 1 0 1
B 1 0 0 0 1 0 1 1
2. p dng thut gii t mu
C 0 0 0 1 1 0 0 0
D 0 0 1 0 0 1 1 0
E 1 1 1 0 0 1 1 1
G 0 1 0 1 1 1 0 0H 1 1 0 0 1 1 0 0
A B C D E F G H
B c 4 4 2 3 6 5 4 4
Kt qu:
Mu 1: D, E.
3 3 1 3 0 4 3 3
2 3 1 2 - 0 2 2
, ,
Mu 3: A, G
Mu 4: H
1 0 1 2 - - 1 11 - 0 0 - - 0 1
0 - 0 - - - 0 08
Ths. Vnh By
8/14/2019 cc Thut Gii t mu
9/18
V D 3
C 6 i bng A, B, C, D, E, F thi u vng trn (1lt bit rn cc trn u sau x ra:
- A u vi B, E.- B u vi A, F.- C u vi D, F.
Do yu cu th lc, mi i ch c thi u 1 trn
hs.V
nh
B
rong u n. y s p x p c c r n u v o c c u n saocho s tun din ra l t nht.
y
9
8/14/2019 cc Thut Gii t mu
10/18
GII QUYT
1. Xc nh th:a) nh: cc trn u.b) Cung: ni gia hai trn u c cng mt i bng tham gia.
Ta c 10 nh: AC, AD, AF, BC, BD, BE, CE, DE, DF, EF.
Ths.V
AC AD AF BC BD BE CE DE DF EF Bc
AC 0 1 1 1 0 0 1 0 0 0 4
nh
By
AF 1 1 0 0 0 0 0 0 1 1 4
BC 1 0 0 0 1 1 1 0 0 0 4
0 1 0 1 0 1 0 1 1 0 5BE 0 0 0 1 1 0 1 1 0 1 5
CE 1 0 0 1 0 1 0 1 0 1 5
10DE 0 1 0 0 1 1 1 0 1 1 6
DF 0 1 1 0 1 0 0 1 0 1 5EF 0 0 1 0 0 1 1 1 1 0 5
8/14/2019 cc Thut Gii t mu
11/18
GII QUYT (TT)
AC AD AF BC BD BE CE DE D
F
EF Bc
AC 0 1 1 1 0 0 1 0 0 0 4
AD 1 0 1 0 1 0 0 1 1 0 5
2. p dng thut gii
AF 1 1 0 0 0 0 0 0 1 1 4
BC 1 0 0 0 1 1 1 0 0 0 4
BD 0 1 0 1 0 1 0 1 1 0 5
BE 0 0 0 1 1 0 1 1 0 1 5
t m u CE 1 0 0 1 0 1 0 1 0 1 5DE 0 1 0 0 1 1 1 0 1 1 6
DF 0 1 1 0 1 0 0 1 0 1 5
EF 0 0 1 0 0 1 1 1 1 0 5
Bc 4 5 4 4 5 5 5 6 5 5
4 4 4 4 4 4 4 0 4 4
0 3 3 3 4 4 3 - 4 4
- 2 3 2 0 3 3 - 3 4
11
Ths. Vnh By
8/14/2019 cc Thut Gii t mu
12/18
THUT GII THAM LAM (GREEDY)
Bc 1:=
Bc 2:i := i+1
Ths.V
T mu i cho tt c cc nh c th t c.
Bc 3:
nh
By
.
12
8/14/2019 cc Thut Gii t mu
13/18
V D
AC AD AF BC BD BE CE DE D
F
EF
AC 0 1 1 1 0 0 1 0 0 0
AD 1 0 1 0 1 0 0 1 1 0
Cho ma trn bn
AF 1 1 0 0 0 0 0 0 1 1
BC 1 0 0 0 1 1 1 0 0 0
BD 0 1 0 1 0 1 0 1 1 0
BE 0 0 0 1 1 0 1 1 0 1
CE 1 0 0 1 0 1 0 1 0 1
DE 0 1 0 0 1 1 1 0 1 1
DF 0 1 1 0 1 0 0 1 0 1Ths
AC AD AF BC BD BE CE DE DF EF
i=1 1 i=1 1 1 i=1 1 1 1
.V
nh
By
AD AF BC BE CE DE DF
i=2 2 i=2 2 2
AF BE CE DE DF
i=3 3 i=3 3 3
13
CE DE DF
i=4 4 i=4 4 4
DE
i=5 5
8/14/2019 cc Thut Gii t mu
14/18
THUT GII SP TH T+ THAM LAM
Bc 1:.
i := 0Bc 2:
Ths.V
i := i+1
T mu i cho tt c cc nh c th t c (xt t tri sang).
nh
By
Lp li bc 2 cho n khi tt c cc nh u c t mu.
14
8/14/2019 cc Thut Gii t mu
15/18
V D 1
AC AD AF BC BD BE CE DE DF EF Bc
AC 0 1 1 1 0 0 1 0 0 0 4
AD 1 0 1 0 1 0 0 1 1 0 5
AF 1 1 0 0 0 0 0 0 1 1 4
Cho ma trn bn
BC 1 0 0 0 1 1 1 0 0 0 4
BD 0 1 0 1 0 1 0 1 1 0 5
BE 0 0 0 1 1 0 1 1 0 1 5
CE 1 0 0 1 0 1 0 1 0 1 5
DE 0 1 0 0 1 1 1 0 1 1 6
DF 0 1 1 0 1 0 0 1 0 1 5
EF 0 0 1 0 0 1 1 1 1 0 5Ths
DE AD BD BE CE DF EF AC AF BC
i=1 1 i=1 1 1
.V
nh
By
AD BD BE CE DF EF AF BC
i=2 2 i=2 2 2
BD CE DF EF AF BC
i=3 3 i=3 3 3 i=3 3 3 3
15
DF EF BC
i=4 4 i=4 4 4
EF
i=5 5
8/14/2019 cc Thut Gii t mu
16/18
V D 2
Mt cuc hi tho c 9 ch a, b, c, d, e, f, g, h, i bit rng ccch sau khn c h din ra tron cn mt bui: ac,
bde, adg, cdf, dfg, egh, ghi.Hy sp xp cc ch vo cc bui sao cho s bui din ra l tT
. hs.V
n
hB
y
16
8/14/2019 cc Thut Gii t mu
17/18
GII QUYT
1. Xc nh th:a) nh: cc ch .
bui.
Ta c 9 nh: a, b, c, d, e, f, g, h, i.Ma trn quan h (hay th quan h nh sau):
Ths.
a b c d e f g h i Bc
a 0 1 1 1
a b c d e f g h i Bc
a 0 0 1 1 0 0 1 0 0
a b c d e f g h i Bc
a 0 0 1 1 0 0 1 0 0 3
nh
By
b 0 1 1
c 0 1 1
d 0 1 1 1
b 0 0 1 1 0 0 0 0
c 0 1 0 1 0 0 0
d 0 1 1 1 0 0
b 0 0 0 1 1 0 0 0 0 2
c 1 0 0 1 0 1 0 0 0 3
d 1 1 1 0 1 1 1 0 0 6
e 0 1 1f 0 1
0 1 1
e 0 0 1 1 0f 0 1 0 0
0 1 1
e 0 1 0 1 0 0 1 1 0 4f 0 0 1 1 0 0 1 0 0 3
1 0 0 1 1 1 0 1 1 617
h 0 1
i 0
h 0 1
i 0
h 0 0 0 0 1 0 1 0 1 3
i 0 0 0 0 0 0 1 1 0 2
8/14/2019 cc Thut Gii t mu
18/18
V D 3
Cho ng nm giao thng nh sau trong BE l ng 1 chiu:
AE Yu cu:
1. Xc nh th.
D
2. T mu th.Sao cho ti mi thi im, cc
tuyn lu thng khng giao
B
.
C
18
Ths. Vnh By