Jip J. Dekker
f2a1c4e389
git-subtree-dir: software/mza git-subtree-split: f970a59b177c13ca3dd8aaef8cc6681d83b7e813
74 lines
1.8 KiB
MiniZinc
74 lines
1.8 KiB
MiniZinc
% RUNS ON mzn20_fd
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% RUNS ON mzn-fzn_fd
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% RUNS ON mzn20_fd_linear
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% RUNS ON mzn20_mip
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%------------------------------------------------------------------------------%
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% trucking.mzn
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% Jakob Puchinger
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% December 2007
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% vim: ft=zinc ts=4 sw=4 et tw=0
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% Original model comes from Peters Student Tim
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% There are N Trucks which have to can be used in every time period,
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% Each truck can transport a given Load of material.
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% Each truck has an associated cost.
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% In each time period a demand has to be fulfilled.
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% Truck1 and Truck2 have some further constraints, disallowing
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% them to be used more than once in consecutive or two consecutive time periods.
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% The goal is to minimise the cost
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%------------------------------------------------------------------------------%
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% Time Periods
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int: T;
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% Trucks
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int: N;
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1..N: Truck1;
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1..N: Truck2;
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array[1..T] of int: Demand;
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array[1..N] of int: Cost;
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array[1..N] of int: Loads;
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array[1..N, 1..T] of var 0..1: x;
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constraint
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forall(t in 1..T)(
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sum(i in 1..N)( Loads[i] * x[i,t]) >= Demand[t]
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);
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constraint
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forall(tau in 1..T-2)(
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sum(t in tau..tau+2)( x[Truck1, t] ) <= 1
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);
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constraint
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forall(tau in 1..T-1)(
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sum(t in tau..tau+1)( x[Truck2, t] ) <= 1
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);
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solve minimize
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sum(i in 1..N)(sum(t in 1..T )( Cost[i] * x[i,t] ));
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% required for showing the objective function
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var int: obj;
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constraint
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obj = sum(i in 1..N)(sum(t in 1..T )( Cost[i] * x[i,t] ));
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output
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[ "Cost = ", show( obj ), "\n" ] ++
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[ "X = \n\t" ] ++
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[ show(x[i, t]) ++ if t = T then "\n\t" else " " endif |
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i in 1..N, t in 1..T ] ++
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[ "\n" ];
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%------------------------------------------------------------------------------%
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% Data
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T = 6;
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N = 4;
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Cost = [30, 27, 23, 20];
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Loads = [20, 18, 15, 13];
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Demand = [27, 11, 14, 19, 25, 22];
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Truck1 = 3;
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Truck2 = 4;
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