That it segfaulted is pretty useless information, it technically narrows it down a bit, but you might as well anyway be saying it crashed. Seeing stdout is not what a debugger is used for. You can do that in other ways.
What a debugger is actually used for is breaking into the code, viewing variables and the stack, and in some cases, rewind in the case of time travel debugging with something like rr or WinDbg. However, as was said before to you, since you do not have debug information, it will be very hard to debug the program without very good experience with programming and especially assembly.
Also, I think in these cases, you will find Valgrind more helpful than simply using gdb.