16 lines
716 B
Modula-2
16 lines
716 B
Modula-2
set Cities ordered;@\Vlabel{line:back:ampl:parstart}@
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set Paths := {i in Cities, j in Cities: ord(i) < ord(j)};
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param cost {Paths} >= 0;@\Vlabel{line:back:ampl:parend}@
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var Take {Paths} binary;@\Vlabel{line:back:ampl:var}@
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minimize TotalCost: sum {(i,j) in Paths} cost[i,j] * Take[i,j];@\Vlabel{line:back:ampl:goal}@
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subj to Tour {i in S}:@\Vlabel{line:back:ampl:con1}@
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sum {(i,j) in Paths} Take[i,j] + sum {(j,i) in Paths} Take[j,i] = 2;
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var Order {Cities} >= 1, <= card(Cities);@\Vlabel{line:back:ampl:compstart}@
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let Order[first(Cities)] = 1;
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subj to SubtourElimation {(i,j) in Cities: ord(i) < ord(j)}:
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(Order[i] - Order[j] + (card(Cities) + 1)*Take[i,j]) <= card(Cities);@\Vlabel{line:back:ampl:compend}@
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