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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。 ( h+ Y D, S0 x$ }% Y
以下是lingo的代码& S) `! ]% ?0 \; G1 \+ x9 |- k0 w
sets:
& p0 U( X: O! i8 N3 Y* `nodes/A,B,C,D,E,F,G,H,I,J,K,L/;
1 V3 B/ E( p9 y& Tarcs(nodes,nodes)/
" x1 z- t- k- {( {1 w; xA,B A,E% k9 b/ i! o" q% X" G
B,C B,E B,F0 g( Q4 L0 l) c( ~8 {. H
C,B C,D9 B, B; l) m! R2 \! J8 h" @
D,C D,H9 I& h& N) s, Z. ~ j. A
E,A E,F; t, S6 v. V% Y/ s9 U! B
F,B F,E F,G F,I F,J
1 M* z& W1 B* p0 s8 nG,C G,F G,H G,K7 f: M/ h: E1 l: J/ V9 f( [
H,D H,K H,L' A. {- P' u$ q
I,E I,J
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K,G K,J. a" T1 T" A M! z j% t2 c
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endsets
" a% |5 S+ R5 {data:) P) x1 I. |' x7 U' k: d1 r* S
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150 165
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140 100
( |( o3 D6 a4 }! H# C100 190; Q( m! [& k" H
165 144
1 {) N6 n0 J& ?0 U& g6 A170 144 128 218 174
, g. f0 E) c2 z0 `4 T Z7 I200 122 109 185+ N7 H; i# v3 _6 D m, M
180 141 190
! J# Y0 L$ B9 T% i% s4 C% {194 148
, v) U/ w* F7 _* ?174 2330 I* x* p% [1 u4 s
185 135
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& G& X3 a6 x2 x, H" c. ]n = @size(nodes);
3 d2 |9 J/ f, c! o* Mmin = @sum(arcs: c * x);
' P2 h" Q# M( b' w* Y3 i0 d@for(nodes(i):: l! u# m$ l/ G, c% Q
@sum(arcs(i,j):x(i,j))=@sum(arcs(k,i):x(k,i))
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+ W: g9 }1 }; @, R2 @) h@for(arcs: @bnd(1,x,9)); & g) e& b) ?& u/ U# B
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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:
+ _; h, V* s. R. b6 U# HP11 = {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];
" j4 g+ v- i4 s; V% H7 q, Iopen[1000]
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