|
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。
/ v h: r6 B) _1 c- A& {# L以下是lingo的代码
' H+ P" w- v; N. d# l" Bsets:8 b! M, e9 M; \' q
nodes/A,B,C,D,E,F,G,H,I,J,K,L/;3 Q9 L: \, ?" ?9 m# d5 `+ E* m2 J! v
arcs(nodes,nodes)/
; V- B3 i# R6 ?, r1 p: `A,B A,E
, ^' Z8 j1 Y% ~2 b I. DB,C B,E B,F# y" j8 F; B1 X4 ]
C,B C,D, ^, B* \/ i4 K. r O" \; h7 s
D,C D,H& Y) |: i$ E5 X, ]: `
E,A E,F
& ?! @0 |6 b8 R7 B4 f! HF,B F,E F,G F,I F,J* p& C# T5 T2 `
G,C G,F G,H G,K, K: D4 l" t x' i
H,D H,K H,L+ K" X+ Y: y5 _8 |; D$ g
I,E I,J, Z% A6 t( a# v
J,F J,G+ s8 K0 N: s. E1 U
K,G K,J; y" M; S/ ~& n; h
L,K# X$ y- M9 U4 G$ N& J
/: c, x;% c# K5 V! S6 s/ K8 S9 }9 z; K
endsets- f/ E5 o" t# v) R- _2 K! o
data:
" I& v [7 Y4 j) Qc=! d5 _, l: Q6 p
150 165# ? U$ B* _# \% m& i: O! L6 K5 P8 d
130 230 160
3 n: V* u* ]8 Q6 y140 100, o. K" i0 y7 \5 Z
100 190
l N1 Q2 n) P* k- X165 144 K8 V9 X# R) X7 r
170 144 128 218 174# ^( z' X d2 |
200 122 109 185/ N: X& O+ ]% K: R8 |% z
180 141 1909 Y2 |7 T: g* F M m- D0 \6 |
194 148
: s6 g7 s4 w. M. E174 233
- g7 K1 d& _' U/ h1 v185 135% K: |4 i5 ?! D, z
110;
Q C: @# S6 [. k% M8 w/ V5 ~enddata6 p" K0 J3 X2 n k: a& j5 @
n = @size(nodes);) T: i9 F' \1 ^5 V" ~
min = @sum(arcs: c * x);5 P- s+ p8 L, D [; Z* B- o$ G6 i
@for(nodes(i):
8 n R% h# _; ~. I) q) U4 C5 P& o@sum(arcs(i,j):x(i,j))=@sum(arcs(k,i):x(k,i))& Y+ q$ B4 L4 l& ^' }5 F C2 Y
);" E) R6 ` q( Q% w/ s# t4 ~& d
@for(arcs: @bnd(1,x,9)); # \, @' m. ] Y% _
2 n# e2 [1 m: }! s* b" \. D
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( Y, t* o- V3 ]
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]; ) S8 M2 T7 t- d) U8 A j/ z& H+ C
open[1000] ; r+ U% k8 L9 W2 s
4 [. @4 ?; ~1 A' J; t |