Hi, I'm working with GNU/Linux, Debian Sarge, libboost-graph1.28.0, gcc
version 2.95.4 20011002 (Debian prerelease).
I'm quite new to this, so I don't know if I'll be able to explain my
problem correctly. It seems to me as if when I declare a graph, it
writes on memory already used by another data structure. The parts of
the code that I consider relevant are (.hpp and .cpp merged)
-------------------
|
|
\|/
-------------------
#include <utility> // for std::pair
#include /* for namespace boost
* vertex_index_t
* edge_weight_t
* listS
* undirectedS
*/
using namespace boost;
namespace boost {
enum vertex_to_be_spanned_t { // used to mark vertices of W
vertex_to_be_spanned
};
BOOST_INSTALL_PROPERTY(vertex, to_be_spanned);
}
namespace steiner {
typedef std::pair Edge; // type of edges
/* Steiner Problem Graph:
* - multigraph
* - add_edge(), ... stability and speed, bad space overhead
* - vertex indices, edge weights
*/
typedef property >
VertexProperty;
typedef property EdgeProperty;
typedef adjacency_list SteinerGraph;
}
namespace steiner {
#define EX_FORMAT "not a valid steiner problem file";
}
#include <iostream> // for std::cout
#include <fstream> // for std::ifstream
using namespace steiner;
namespace steiner {
int readsteinerORfile(steiner::SteinerGraph& g, char *s);
}
namespace steiner {
inline void skipspaces(std::ifstream& fp, char& c);
}
namespace steiner {
inline int readchar2int(std::ifstream& fp, char& c);
}
/* int main(int argc, char *argv[])
* --------------------------------
* *argv[] (IN): file names array
* --------------------------------
* return n: n files were succesfully read, n > 0
* return 0: no files could be read
* return -1: unexpected error
* --------------------------------
* read steiner problem from files
*/
int main(int argc, char *argv[]) {
...
SteinerGraph g;
nf = steiner::readsteinerORfile(g, argv[i]);
...
}
/* int readsteinerORfile(VertexListGraph& g, char *s)
* --------------------------------
* g (OUT): graph read from file
* *s (IN): file name
* --------------------------------
* return 1: file successfully read
* return 0: file could not be read
* return -1: unexpected error
* --------------------------------
* read steiner problem from one file
*/
namespace steiner {
int readsteinerORfile(steiner::SteinerGraph& g, char *s) {
...
int num_edg=0, num_ver=0, // number of edges, vertices
num_verw=0; // number of non-steiner vertices
char c; // file reader
int i; // counter
int x; // temp value
int *weight_array=NULL; // edge weights read from file
Edge *edge_array=NULL; // array of edges read from file
int *w_array=NULL; // vertices of W
...
weight_array = new int[num_edg];
if (weight_array == NULL) throw (char *)EX_MEM;
edge_array = new Edge[num_edg];
if (edge_array == NULL) throw (char *)EX_MEM;
w_array = new int[num_verw];
if (w_array == NULL) throw (char *)EX_MEM;
...
*************** HERE *******************
/* creation of graph object */
g.clear();
g = SteinerGraph(num_ver);
*************** HERE *******************
...
}
}
-------------------
|
|
\|/
-------------------
And what happens? If I print the contents of w_array[] at the first
"HERE", I get
Puf(W(0)=0 )!
Puf(W(1)=1 )!
Puf(W(2)=2 )!
Puf(W(3)=3 )!
but if I print them again at the second "HERE", I get
Puf(W(0)=8 )!
Puf(W(1)=1 )!
Puf(W(2)=2 )!
Puf(W(3)=-15 )!
Does anybody knows what could be happening? Thank you.
Regards,
Ramón Casero.
