Compilare: main.cpp: In function 'int main()': main.cpp:81:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < sol.size(); i++) ~~^~~~~~~~~~~~ main.cpp:50:40: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen ("armonica.in", "r", stdin); ^ main.cpp:51:42: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen ("armonica.out", "w", stdout); ^ main.cpp:55:23: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf ("%lld", &b); ^