It is also useful to profile your program under the development stage. You would then compile with

c++  -pg -O3 -c  mycode.cpp
c++  -pg -O3 -o  mycode.exe  mycode.o

After you have run the code you can obtain the profiling information via

gprof mycode.exe >  ProfileOutput

When you have profiled properly your code, you must take out this option as it slows down performance. For memory tests use valgrind. An excellent environment for all these aspects, and much more, is Qt creator.