> But in my problem i need functions for breaking only specified rows
> or specified columns that are interchangeable, for example : rows 4
> and 7 of the matrix are interchangeable, or for example: column 2 and
> 5 only are interchangeable and not all rows are interchangeable and
> not all columns are interchangeable.
Here is how you might interchange only two rows of a matrix. I took
the BIBD example and kept only the row-sum and column-sum constraints:
BIBD(const BIBDOptions& o)
: opt(o), _p(*this,opt.rows*opt.cols,0,1) {
Matrix<BoolVarArray> p(_p,opt.cols,opt.rows);
// r ones per row
for (int i=0; i<opt.rows; i++)
linear(*this, p.row(i), IRT_EQ, opt.r);
// k ones per column
for (int j=0; j<opt.cols; j++)
linear(*this, p.col(j), IRT_EQ, opt.k);
For a 3x3 matrix with 1 one per row and column, this has 6 solutions:
1 0 0
0 1 0
0 0 1
1 0 0
0 0 1
0 1 0
0 1 0
1 0 0
0 0 1
0 1 0
0 0 1
1 0 0
0 0 1
1 0 0
0 1 0
0 0 1
0 1 0
1 0 0
Then I put the first row and second row in a BoolVarArgs object and
give it as a variable sequence symmetry:
Symmetries s;
BoolVarArgs a2;
a2 << p.row(0);
a2 << p.row(1);
s << VariableSequenceSymmetry(a2, opt.cols);
Now there are only three solutions:
1 0 0
0 1 0
0 0 1
1 0 0
0 0 1
0 1 0
0 1 0
0 0 1
1 0 0
> an other case that i need is: where we have the following
> permutations of rows of a matrix ( rotation of rows):
>
> row 1 takes the content of row 2
> row 2 takes the content of row 3
> .
> .
> row i takes the content of row (i+1)
> .
> .
> row n takes the content of row 1
For this case you can do something similar:
BoolVarArgs a;
for (int i = 0 ; i < opt.rows ; i++) {
a << p.row(i);
}
for (int i = 0 ; i < opt.rows ; i++) {
a << p.row((i+1)%opt.rows);
}
s << VariableSequenceSymmetry(a, opt.rows*opt.cols);
Now there are only two solutions:
1 0 0
0 1 0
0 0 1
1 0 0
0 0 1
0 1 0
The two symmetries could be combined too.
Note that the number of solutions found can depend on the search order;
if you do the same exercise with INT_VAL_MIN instead of MAX, you'll get
different results.
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