Compilare: user.cpp: In function ‘void do_the_thing(int)’: user.cpp:24:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i = 0; i < rez.size(); i++) { ^ user.cpp: In function ‘int main()’: user.cpp:32:12: warning: unused variable ‘j’ [-Wunused-variable] int i, j; ^ user.cpp:33:41: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("ciclueuler.in", "r", stdin); ^ user.cpp:34:43: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("ciclueuler.out", "w", stdout); ^ user.cpp:35:27: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &N, &M); ^ user.cpp:37:31: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &x, &y); ^