Compilare: user.cpp: In function ‘int main()’: user.cpp:35:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < a.size(); i++) ^ user.cpp:41:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < b.size(); i++) ^ user.cpp:25:40: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("readunare.in", "r", stdin); ^ user.cpp:26:42: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("readunare.out", "w", stdout); ^