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ortools-clone/examples/cpp/print_dimacs_assignment.cc

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// Copyright 2010-2012 Google
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#include "cpp/print_dimacs_assignment.h"
#include <cstdio>
#include <string>
#include "base/logging.h"
#include "base/stringprintf.h"
#include "graph/ebert_graph.h"
#include "graph/linear_assignment.h"
namespace operations_research {
static void WriteOrDie(const char* buffer,
size_t item_size,
size_t buffer_length,
FILE* fp) {
size_t written = fwrite(buffer, item_size, buffer_length, fp);
if (written != buffer_length) {
fprintf(stderr, "Write failed.\n");
exit(1);
}
}
void PrintDimacsAssignmentProblem(
const LinearSumAssignment<ForwardStarGraph>& assignment,
const TailArrayManager<ForwardStarGraph>& tail_array_manager,
const string& output_filename) {
FILE* output = fopen(output_filename.c_str(), "w");
const ForwardStarGraph& graph(assignment.Graph());
string output_line = StringPrintf("p asn %d %d\n",
graph.num_nodes(),
graph.num_arcs());
WriteOrDie(output_line.c_str(), 1, output_line.length(),
output);
for (LinearSumAssignment<ForwardStarGraph>::BipartiteLeftNodeIterator
node_it(assignment);
node_it.Ok();
node_it.Next()) {
output_line = StringPrintf("n %d\n", node_it.Index() + 1);
WriteOrDie(output_line.c_str(), 1, output_line.length(),
output);
}
tail_array_manager.BuildTailArrayFromAdjacencyListsIfForwardGraph();
for (ForwardStarGraph::ArcIterator arc_it(assignment.Graph());
arc_it.Ok();
arc_it.Next()) {
ArcIndex arc = arc_it.Index();
output_line = StringPrintf("a %d %d %lld\n",
graph.Tail(arc) + 1,
graph.Head(arc) + 1,
assignment.ArcCost(arc));
WriteOrDie(output_line.c_str(), 1, output_line.length(),
output);
}
}
} // namespace operations_research