Hi, Sorry to reply so late,because I'm working on the CUDA implementation these days. I'm not very familiar to the gdb,so I need some time to learn it.At first I doubt that my code's problem is at the definition of array,but after I modified such as "E edges[num_edges]" to "E *edges = new E[num_edges]",the result is always wrong even the input size is small.But I indeed don't understand the difference between two froms. Thank you very much! Wang wei 2010/8/27 Stephen Woodbridge

On 8/27/2010 4:52 AM, 王伟 wrote:

...

Hi, I'm studying MST algorithms in GPU recently.I need BGL implementation as coparison,But I have a problem in using prim_minimum_spanning_tree.hpp.The problem is:when I use large input(e.g. >1M),there's a "segmnetation error" problem.But when the input(e.g. 1K) is small,the result is noproblem. I haven't found know the reason yet.My complier is gcc 4.1.2,OS is RHEL5. Help would be appreciated. Thanks in advance. Wang wei The complete code is in the attachment.

There are a couple of things that would be helpful to try and report:

1) run your executable in gdb

gdb ./BGLPrim run <arguments> backtrace quit

and report the backtrace output.

2) run your code under valgrind

valgrind --leak-check=summary ./BGLPrim <arguments>

This will run slower, but will print out some information at the end of the execution that might also be very helpful.

-Steve _______________________________________________ Boost-users mailing list Boost-users@lists.boost.org http://lists.boost.org/mailman/listinfo.cgi/boost-users

Hi! You're allocating edges and weights on the stack: E edges[num_edges]; int weights[num_edges]; This is not a good idea, because stack space is very limited compared to the heap. Allocate these two vectors on the heap instead: E *edges = new E[num_edges]; int *weights = new int[num_edges]; .... delete[] edges; delete[] weights; Cheers, Gabe