Jip J. Dekker
fad1b07018
git-subtree-dir: software/minizinc git-subtree-split: 4f10c82056ffcb1041d7ffef29d77a7eef92cf76
41 lines
1.4 KiB
MiniZinc
41 lines
1.4 KiB
MiniZinc
include "all_different.mzn";
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include "disjunctive.mzn";
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include "fzn_cumulative.mzn";
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include "fzn_cumulative_reif.mzn";
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/** @group globals.scheduling
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Requires that a set of tasks given by start times \a s, durations \a d, and
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resource requirements \a r, never require more than a global resource bound
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\a b at any one time.
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Assumptions:
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- forall \p i, \a d[\p i] >= 0 and \a r[\p i] >= 0
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*/
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predicate cumulative(array[int] of var int: s,
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array[int] of var int: d,
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array[int] of var int: r, var int: b) =
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assert(index_set(s) == index_set(d) /\ index_set(s) == index_set(r),
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"cumulative: the 3 array arguments must have identical index sets",
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if length(s) >= 1 then
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assert(lb_array(d) >= 0 /\ lb_array(r) >= 0,
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"cumulative: durations and resource usages must be non-negative",
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if
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%% the previous test will not work for resources usages like [2,3,3,4,4] with a bound of 4 since the 2 appears exactly once
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let { int: mr = lb_array(r);
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int: mri = arg_min([ lb(r[i]) | i in index_set(r) ]) } in
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forall(i in index_set(r))
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(is_fixed(r[i]) /\ (fix(r[i]) + mr > ub(b) \/ i = mri))
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then
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if forall(i in index_set(d))(is_fixed(d[i]) /\ fix(d[i]) == 1)
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then
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all_different(s)
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else
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disjunctive(s, d)
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endif
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else
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fzn_cumulative(s, d, r, b)
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endif
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)
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endif);
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