Global constraints by composition: lexicographic ordering with sums
نویسندگان
چکیده
We introduce a new global constraint which combines together a lexicographic ordering constraint with some sum constraints. Applications for this constraint include balanced incomplete block designs and the ternary Steiner problem. We develop an efficient linear time algorithm for propagating this constraint. This combination of constraints increases the filtering, leading to significant decreases in the size of the search tree. The benefits are especially apparent when the search strategy and the symmetry breaking, provided by the lexicographic or-
منابع مشابه
Combining Symmetry Breaking with Other Constraints: Lexicographic Ordering with Sums
We introduce a new global constraint which combines together the lexicographic ordering constraint with some sum constraints. Lexicographic ordering constraints are frequently used to break symmetry, whilst sum constraints occur in many problems involving capacity or partitioning. Our results show that this global constraint is useful when there is a very large space to explore, such as when th...
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