Compilare: user.cpp: In function ‘int main()’: user.cpp:69:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < sol.size(); i++) ^ user.cpp:38:18: warning: unused variable ‘sx’ [-Wunused-variable] double x, y, sx = 0, sy = 0; ^ user.cpp:38:26: warning: unused variable ‘sy’ [-Wunused-variable] double x, y, sx = 0, sy = 0; ^