*

*Mc ch ca tr tu nhn to: Theo Winton: mc ch chnh ca tr tu nhn to l lm cho cc my tnh in t thng minh hn, c ch hn v gip khm ph cc quy lut v kh nng hot ng tr tu ca con ngi. T y s tc ng trc tip lm cho con ngi thng minh hn, hot ng c hiu qu hn.

*M hnh c hnh:

*Vai tr tr tu nhn to:

*Cc nh nghaTr tu nhn to: tr tu nhn to c th c nh ngha nh mt h thng my mc c kh nng thc hin nhng hnh ng ca con ngi c xem l thng minh.Thng minh: s nghin cu, s thu thp thng tin tiu biu nh: c gng hc nhng tng x l ca b no con ngi, bao gm c vic nghin cu s vt c tng, c ngha, c s ch , nhn dng, hiu vn v sng to ra vn .

*Nhn to: C ngha l c gng s dng my tnh xy dng nhng h thng nhn to bt chc c tnh ca vic thu thp thng tin mt cch thng minh.Cc nh ngha (tt)

*D LIU = Ch ci, con s, hnh nh ring r, ri rc, khng mang mt ngha no. THNG TIN = Cc d liu c sp xp theo mt quan h no . TRI THC = mi quan h gia cc d liu c xc nh mt cch tng minh.

*V D : D LIU : 1, 1, 3, 5, 2, 7, 11, ... THNG TIN : 1, 1, 2, 3, 5, 8, 13, 21, 34, .... TRI THC : Un = Un-1 + Un-2.

*D LIUTHNG TIN TRI THC tru tngS lng

*Mt s thut ton:Phng php gii quyt vn theo hng xc nh trc tip li gii: p dng mt cng thc c th tnh ra li gii trong mi trng hp c s dng. y l phng php tt nht (theo ngha cc cng thc tm ra v c chng minh s cho li gii trong mi trng hp.) v hu hiu nht.V d: Lp chng trnh tnh S = 1 + 2 + 3 + + n (n N)Write(Nhp n=);Readln(n);Write( S = , n*(n-1)/2);

*Mt s thut ton (tt)2. Phng php Vt cn: Gi s chng ta gii bi ton P trn min D, xDBc 1: xD, P(x) ng: in kt qu v dng (success).Bc 2: D := D \ {x}: Loi trng hp ny nu sai.Bc 3: Kim tra D {}+ ng : Goto bc 1.+ Sai: Dng (fail).Lu : i vi phng php ny, vic gii hn D cng nh gii cng nhanh.V d: Tm cc s c ba ch s tha: abc=a3 +b3 +c3Ta c D: 1 a 9 0 b, c 9For a := 1 To 9 DoFor b := 0 To 9 Do For c:=1 To 9 Do If (100*a+10*b+c = a*a*a + b*b*b + c*c*c) then Writeln(a,b,c);

*Mt s thut ton (tt)3. Phng php qui:nh ngha kiu qui:V d: nh ngha s t nhin:1 l s t nhinn l s t nhin th (n-1) cng l s t nhin.Hm qui: Hm f c gi l qui nu: f(x) = f(x, f(x))

*Mt s thut ton (tt)4. Phng php ngu nhin (phng php Monte Carlo):Bi ton: Tnh din tch ca hnh M bt k.+ C th bao hnh M ni tip trong mt hnh vung c cnh l 1 n v.+ Pht ngu nhin N im vo trong hnh vung.+ C Nm im nm trong hnh M.

*Mt s thut ton (tt)Vi n ln, din tch (xp x) hnh M c tnh nh sau:

*Mt s thut ton (tt)V d: Tnh : din tch hnh trn S0 = R2vi R = 1/2 = 4S0

*Mt s thut ton (tt)Function Pi:Real;Varm, i : Integer;x, y : Real;Beginm := 0;For i := 1 To N Do{Pht ngu nhin N im}Beginx := random;{x (0,1)}y := random;{y (0,1)}If (x2 + y2) 1 Then m := m + 1;End;Pi := 4*m/N;End;

*Cc tnh cht ca mt thut ton: Khi xy dng mt thut ton v chng trnh tng ng gii mt bi ton cn phi phn tch:+ Tnh ng n ca thut ton: phi dng cng c ton hc chng minh l ng.+ Tnh n gin ca thut ton: d hiu, d lp trnh, d hiu chnh.+ Tnh ti u ca thut ton (nu c nhiu thut ton).

*Cc tnh cht ca mt thut ton:Lu :Thi gian v b nh l 2 i lng t l nghch, nn nhiu khi tnh cng n gin cng lm chm chng trnh.Thi gian thc hin mt thut ton ph thuc rt nhiu yu t:+ Kch thc ca d liu.+ Kiu lnh+ Tc x l ca my.+ Ngn ng lp trnh.+ Trnh bin dch.

*K thut tm kimMt s bi ton Bi ton m cung:

*K thut tm kim (tt)Cc tiu ha gi thnh: Ngi a th cn xc nh hnh trnh i ngn nht sao cho mi thnh ph i n ng mt ln v quay v thnh ph xut pht.Tr chi: Tic-tac-toe (c caro).Bi ton t mu:Cho mt bn , t mu cho mi nc trn bn sao cho hai nc lng ging (c chung ng bin gii) c hai mu khc nhau.Vn : s mu cn dng ti a l bao nhiu? 1976 ngi ta dng my tnh chng minh c l ch cn dng ti a l 4 mu.

*K thut tm kim (tt)Bi ton taci:

*Biu din bi ton:

*Biu din bi ton (tt)Hu ht cc bi ton u c th pht biu di dng sau: t mt trng thi xut pht hy tm ng dn n mt trng thi kt thc mong mun. Vic tm ng i ny l mt ngh thut gii quyt vn , bao gm cc bc sau:Chn c khng gian tm kim thch hp.Tin hnh tm kim c h thng v c hiu qu trong khng gian tm kim.S dng trit cc ngun tri thc c lin quan trong qu trnh tm kim tng ng vi min i lng c th.

*Biu din bi ton (tt)Khng gian tm kim ca mt vn gii trn my tnh thng c biu din bi mt th hoc mt dng c bit ca th (cy). Sau khi bi ton c biu din di dng th (hoc cy) th:Mi nh l mt giai on ca qu trnh gii (hay l trng thi).Mi cung l mt tc ng bin i qu trnh t giai on ny sang giai on khc.

*Biu din bi ton (tt)

*

*Tm kim rng (Breadth-first search)Hin thc: FIFO queue.

*Breadth-first searchHin thc: FIFO queue.

*Breadth-first searchHin thc: FIFO queue.

*Breadth-first searchHin thc: FIFO queue.

*

Tm kim su (Depth-first search)Hin thc: LIFO queue

*Depth-first searchHin thc: LIFO queue

*Depth-first searchHin thc: LIFO queue

*Depth-first searchHin thc: LIFO queue

*Depth-first searchHin thc: LIFO queue

*Depth-first searchHin thc: LIFO queue

*Depth-first searchHin thc: LIFO queue

*Depth-first searchHin thc: LIFO queue

*Depth-first searchHin thc: LIFO queue

*Depth-first searchHin thc: LIFO queue

*Depth-first searchHin thc: LIFO queue

*Depth-first searchHin thc: LIFO queue

*Tm kim su dn: (Iterative deepening search)Kt hp ca tm kim rng v tm kim su trn c s cho bit mc su n ri tm kim rng ng mi mc su .

*Iterative deepening search l =0

*Iterative deepening search l =1

*Iterative deepening search l =2

*Iterative deepening search l =3

*L mt cy m t cc chn la c th thc hin trong mi bc ca qu trnh gii bi ton. Ton b cy tm kim c tng trng bng mt hnh tam gic. V tr bt u nh, v tr kt thc y

*Su Rng

*Su Rng C th i vo cc ng, nhnh ct (khng th i tip c na) quay luiKhng cn quay luiCh quan tm n hng i chn. Quan tm n tt c hng i tn b nh lu tr

*Su dn Hn ch trng hp i qu su m gp nhnh ctt tn b nh hn. Tn dng c u im rng ca phng php tm theo chiu rng. su gii hn bao nhiu l ?

*Cht nhnhLoi b hng tm kim chc chn khng dn n li gii. Tm kim vi tri thc b sungu tin i theo hng c trin vng nht, hy vng s n li gii nhanh hn, trng hp xu nht quay v vt cn. (nh th no l trin vng nht?)