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要求从1开始,最终回到1,且路径有方向,要求所有路径都经过。
, S- r" ~9 F$ e9 [以下是lingo的代码9 K0 {3 P; a1 `( t
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nodes/A,B,C,D,E,F,G,H,I,J,K,L/;" O0 c& V, }! ~) u
arcs(nodes,nodes)/* ?+ b+ T A' y: F' O& X X
A,B A,E1 E0 o. [$ N2 Y' p s
B,C B,E B,F
4 N) P0 b2 L: s# h/ UC,B C,D0 l3 d. y- ~- ?" M- x. w
D,C D,H
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F,B F,E F,G F,I F,J
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H,D H,K H,L) M. ~$ ~2 U A' X' [) S
I,E I,J$ i( d$ y- E: B0 {4 S
J,F J,G
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c=
: c( O$ v; Q% n m- e$ [+ v9 T- u/ R150 165
; r _5 R7 r) c/ f+ Q5 U# M130 230 160
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100 190
( C: M* R2 d) Q+ F' i165 1440 u& l( X6 V9 f/ e3 v
170 144 128 218 174& b+ S; A9 @6 }" L- I* h
200 122 109 1859 `: i( `+ Q# [" w% y
180 141 190
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174 233
7 `( f* e( Y/ x, l K185 1350 b9 ] ]' T9 H; m* v
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enddata
8 U% A/ U% \! o% L# Nn = @size(nodes);. K8 h9 y) ~ y ~
min = @sum(arcs: c * x);0 B8 _: j) |7 \ y( O$ {- c
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@sum(arcs(i,j):x(i,j))=@sum(arcs(k,i):x(k,i))( n& ^. W8 r' S. _& \: c6 U
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@for(arcs: @bnd(1,x,9)); - z- B7 p' |; W0 e3 W K
* w4 J7 }5 R# P它只能算出路径的步数和路程,并不能得到线路。希望能用mma解决这个问题。 --------------------------------------------------------------------- 自己用mma写的程序对于四点还可以,但是扩展到12点实在繁琐: 9 y- f; Y1 I% H9 P, m$ Q# O! z' m
P11 = {2, 5}; P12 = {150, 165}; P21 = {5, 6}; P22 = {230, 160}; P51 = {1, 6}; P52 = {165, 144}; P61 = {2, 5}; P62 = {170, 144};(*只考虑1、2、5、6四点,P11为第一点“可去往的点”,P12表述对应的路程*) open[q_] := Module[{i = 1, randomD, randomP, D, randomreal, p1, p2, p5, p6, c, u, Df = 80000, uf, path = {1}, pathf = {1}, pb},(*随机搜索*) For[r = 0, r < q, r++, {p1 = {}; p2 = {}; p5 = {}; p6 = {}; u = 0; D = 0; i = 1; randomP = P11; randomD = P12; While[ Length[p1] != 2 || Length[p2] != 2 || Length[p5] != 2 || Length[p6] != 2 || i != 1, randomreal = RandomInteger[{1, Length[randomP]}]; c = randomP[[randomreal]]; AppendTo[path, c];(*Print[path];*) Which[ i == 1 && Product[If[p1[] != c, 1, 0], {i, 1, Length[p1]}] == 1, {AppendTo[p1, c]}, i == 2 && Product[If[p2[] != c, 1, 0], {i, 1, Length[p2]}] == 1, {AppendTo[p2, c]}, i == 5 && Product[If[p5[] != c, 1, 0], {i, 1, Length[p5]}] == 1, {AppendTo[p5, c]}, i == 6 && Product[If[p6[] != c, 1, 0], {i, 1, Length[p6]}] == 1, {AppendTo[p6, c]}]; i = c; D = D + randomD[[randomreal]]; Which[i == 1, {randomP = P11, randomD = P12}, i == 2, {randomP = P21, randomD = P22}, i == 5, {randomP = P51, randomD = P52}, i == 6, {randomP = P61, randomD = P62}]; u = u + 1; If[u > 11, Break[]]; If[Df > D, {Df = D, uf = u, pathf = path, path = {1}}, path = {1}]; } ]; Print[Df, ",", uf, ",", pathf];
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