Compilare: user.cpp: In function ‘void back(int)’: user.cpp:48:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < q.size(); i += 4) ~~^~~~~~~~~~ user.cpp:55:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < ims.size(); ++i) ~~^~~~~~~~~~~~ user.cpp:74:31: warning: variable ‘jumpStart’ set but not used [-Wunused-but-set-variable] point jumpStart = to; ^~~~~~~~~ user.cpp: In function ‘int main()’: user.cpp:125:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 1; i < alive.size(); ++i) { ~~^~~~~~~~~~~~~~