Thut Ton AKT Bc 1: Mi nh n v hm g,h, f n. M nh u tin S0 . Gn g(S0) =0 S dng tri thc b sung c tnh h(S0) Tnh f(S0) = g(S0) + h(S0)

Bc 2: Chn mt nh m vi hm f l min v gi l nh N. Nu N l ch => dng. ng i t nh ban u n nh N l ngn nht v

bng g(N). Nu khng tn ti N th cy biu din vn khng c ng i ti mc tiu =>

dng (bi ton khng li gii) Nu tn ti nhiu hn mt nh N c cng hm fmin th phi kim tra xem trong s

c nh no l ch hay khng? o Nu c => Dng o Nu khng => chn ngu nhin mt trong cc nh v gi l nh N

Bc 3: ng nh N v m mi nh sau N. Vi mi nh S sau N, tnh g(s)=g(N) + g(N ->S) Dng tri thc b sung c tnh hm h(S) Tnh f(S) = g(S) + h(S)

Bc 4: Quay li bc 2

p Dng: p dng thut ton AKT gii bi ton Taci vi c lng nh sau:

trong l s bc phi dch chuyn t nht theo chiu

ngang v chiu dc y ai a v ng v tr bi b.

Start Goal

1 2 3

4 5 6

7 8

Ta c:

1 2 3

4 8 5

7 6

HoangXuanTypewriternh chnh l trng thi, nguyn c ci

HoangXuanTypewriter

V h = 0 => ch => dng Kt lun: ng i ngn nht g = 5

g = 0

h = 5

f = 5

g = 1

h = 6 f = 7

g = 1

h = 6 f = 7

g = 1

h = 4 f = 5

g = 2 h = 3

f = 5

g = 3

h = 2

f = 5

g = 4

h = 3 f = 7

g = 4 h = 1

f = 5

g = 3

h = 4

f = 7

g = 4 h = 3

f = 7

g = 5

h = 2 f = 7

g = 5

h = 0

f = 5