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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。 $ d. I/ _& n( U, e. }
以下是lingo的代码
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nodes/A,B,C,D,E,F,G,H,I,J,K,L/;+ a2 P7 J4 W2 u; G2 {
arcs(nodes,nodes)/
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B,C B,E B,F+ y2 y9 r- L4 b3 G' Q
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endsets) [) P& X0 z5 S/ i
data:
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6 @! f- ]" a" b) \9 N5 M150 165
2 S+ G% z/ b3 d% U! ?/ Z, Q130 230 1602 C9 O& O9 r1 B W
140 100
( E4 X7 b4 L' ]" d100 190
4 C# u7 m$ m- s' Q# }165 144
7 }8 z3 s) \7 c* \. f8 h0 N170 144 128 218 174
2 X9 N I% P( E! O. w3 r200 122 109 185
2 {$ R8 B3 b( p180 141 190; m. E K; f; M4 u8 z9 o
194 1489 }5 O3 p$ w" o) a' I0 o9 q4 G0 E
174 233
' N5 e8 L% A: v/ t185 135. H m% v$ h ?8 g. f, D
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enddata- @+ S2 u1 t' o; o
n = @size(nodes);6 l ?' k4 d' x$ L3 m8 ]; ]
min = @sum(arcs: c * x);, i, M4 S/ Z9 S+ z9 b
@for(nodes(i):
% ~3 B) C3 M' D@sum(arcs(i,j):x(i,j))=@sum(arcs(k,i):x(k,i))
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" S0 C; d7 q& r3 x@for(arcs: @bnd(1,x,9));
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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: - G2 ^9 _2 {9 w d, U @; z, d, c
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]; + Q2 n/ \6 r# C8 I+ k/ }
open[1000]
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