magic-square.cpp
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/* -*- mode: C++; c-basic-offset: 2; indent-tabs-mode: nil -*- */
/*
* Main authors:
* Christian Schulte <schulte@gecode.org>
*
* Copyright:
* Christian Schulte, 2001
*
* This file is part of Gecode, the generic constraint
* development environment:
* http://www.gecode.org
*
* Permission is hereby granted, free of charge, to any person obtaining
* a copy of this software and associated documentation files (the
* "Software"), to deal in the Software without restriction, including
* without limitation the rights to use, copy, modify, merge, publish,
* distribute, sublicense, and/or sell copies of the Software, and to
* permit persons to whom the Software is furnished to do so, subject to
* the following conditions:
*
* The above copyright notice and this permission notice shall be
* included in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
* LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
* OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
* WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*
*/
#include <gecode/driver.hh>
#include <gecode/int.hh>
#include <gecode/minimodel.hh>
using namespace Gecode;
class MagicSquare : public Script {
private:
const int n;
IntVarArray x;
public:
enum {
BRANCH_SIZE,
BRANCH_AFC_SIZE
};
MagicSquare(const SizeOptions& opt)
: Script(opt), n(opt.size()), x(*this,n*n,1,n*n) {
// Number of fields on square
const int nn = n*n;
// Sum of all a row, column, or diagonal
const int s = nn*(nn+1) / (2*n);
// Matrix-wrapper for the square
Matrix<IntVarArray> m(x, n, n);
for (int i = n; i--; ) {
linear(*this, m.row(i), IRT_EQ, s, opt.ipl());
linear(*this, m.col(i), IRT_EQ, s, opt.ipl());
}
// Both diagonals must have sum s
{
IntVarArgs d1y(n);
IntVarArgs d2y(n);
for (int i = n; i--; ) {
d1y[i] = m(i,i);
d2y[i] = m(n-i-1,i);
}
linear(*this, d1y, IRT_EQ, s, opt.ipl());
linear(*this, d2y, IRT_EQ, s, opt.ipl());
}
// All fields must be distinct
distinct(*this, x, opt.ipl());
// Break some (few) symmetries
rel(*this, m(0,0), IRT_GR, m(0,n-1));
rel(*this, m(0,0), IRT_GR, m(n-1,0));
switch (opt.branching()) {
case BRANCH_SIZE:
branch(*this, x, INT_VAR_SIZE_MIN(), INT_VAL_SPLIT_MIN());
break;
case BRANCH_AFC_SIZE:
branch(*this, x, INT_VAR_AFC_SIZE_MAX(opt.decay()), INT_VAL_SPLIT_MIN());
break;
}
}
MagicSquare(MagicSquare& s) : Script(s), n(s.n) {
x.update(*this, s.x);
}
virtual Space*
copy(void) {
return new MagicSquare(*this);
}
virtual void
print(std::ostream& os) const {
// Matrix-wrapper for the square
Matrix<IntVarArray> m(x, n, n);
for (int i = 0; i<n; i++) {
os << "\t";
for (int j = 0; j<n; j++) {
os.width(2);
os << m(i,j) << " ";
}
os << std::endl;
}
}
};
int
main(int argc, char* argv[]) {
SizeOptions opt("MagicSquare");
opt.iterations(1);
opt.size(7);
opt.branching(MagicSquare::BRANCH_SIZE);
opt.branching(MagicSquare::BRANCH_SIZE, "size");
opt.branching(MagicSquare::BRANCH_AFC_SIZE, "afc-size");
opt.parse(argc,argv);
Script::run<MagicSquare,DFS,SizeOptions>(opt);
return 0;
}
// STATISTICS: example-any
Gecode::Driver::ScriptBase< Driver::IgnoreStepOption< Space > >::run
static void run(const Options &opt, Script *s=NULL)
Gecode::IntVarArgs
Passing integer variables.
Definition int.hh:656
Gecode::Matrix
Matrix-interface for arrays.
Definition minimodel.hh:2161
Gecode::Matrix::col
Slice< A > col(int c) const
Access column c.
Definition matrix.hpp:183
Gecode::Matrix::row
Slice< A > row(int r) const
Access row r.
Definition matrix.hpp:177
Gecode::SizeOptions
Options for scripts with additional size parameter
Definition driver.hh:675
Gecode::Space
Computation spaces.
Definition core.hpp:1742
MagicSquare
Example: Magic squares
Definition magic-square-partial.cpp:61
MagicSquare::BRANCH_AFC_SIZE
@ BRANCH_AFC_SIZE
Branch by size over AFC.
Definition magic-square-partial.cpp:76
MagicSquare::BRANCH_SIZE
@ BRANCH_SIZE
Branch by size.
Definition magic-square-partial.cpp:75
MagicSquare::MagicSquare
MagicSquare(MagicSquare &s)
Constructor for cloning s.
Definition magic-square.cpp:109
MagicSquare::MagicSquare
MagicSquare(const SizeOptions &opt)
Post constraints.
Definition magic-square.cpp:64
MagicSquare::print
virtual void print(std::ostream &os) const
Print solution.
Definition magic-square.cpp:120
MagicSquare::copy
virtual Space * copy(void)
Copy during cloning.
Definition magic-square.cpp:115
Test::Options::parse
void parse(int argc, char *argv[])
Parse commandline arguments.
Definition test.cpp:120
driver.hh
int.hh
Gecode::Script
Driver::ScriptBase< Driver::IgnoreStepOption< Space > > Script
Base-class for scripts.
Definition driver.hh:801
Gecode::branch
void branch(Home home, const FloatVarArgs &x, FloatVarBranch vars, FloatValBranch vals, FloatBranchFilter bf=nullptr, FloatVarValPrint vvp=nullptr)
Branch over x with variable selection vars and value selection vals.
Definition branch.cpp:39
Gecode::linear
void linear(Home home, const FloatVarArgs &x, FloatRelType frt, FloatVal c)
Post propagator for .
Definition linear.cpp:41
Gecode::rel
void rel(Home home, FloatVar x0, FloatRelType frt, FloatVar x1)
Post propagator for .
Definition rel.cpp:68
Gecode::IRT_EQ
@ IRT_EQ
Equality ( ).
Definition int.hh:926
Gecode::IRT_GR
@ IRT_GR
Greater ( ).
Definition int.hh:931
minimodel.hh
Gecode
Gecode toplevel namespace
Gecode::INT_VAL_SPLIT_MIN
IntValBranch INT_VAL_SPLIT_MIN(void)
Select values not greater than mean of smallest and largest value.
Definition val.hpp:75
Gecode::INT_VAR_AFC_SIZE_MAX
IntVarBranch INT_VAR_AFC_SIZE_MAX(double d=1.0, BranchTbl tbl=nullptr)
Select variable with largest accumulated failure count divided by domain size with decay factor d.
Definition var.hpp:236
Gecode::distinct
void distinct(Home home, const IntVarArgs &x, IntPropLevel ipl=IPL_DEF)
Post propagator for for all .
Definition distinct.cpp:46
Gecode::INT_VAR_SIZE_MIN
IntVarBranch INT_VAR_SIZE_MIN(BranchTbl tbl=nullptr)
Select variable with smallest domain size.
Definition var.hpp:206
Test::opt
Options opt
The options.
Definition test.cpp:97
main
int main(int argc, char *argv[])
Definition test.cpp:208