Compilare: user.cpp: In function ‘bool cuplaj(int)’: user.cpp:14:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < l[x].size(); ++i) ~~^~~~~~~~~~~~~ user.cpp:21:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < l[x].size(); ++i) ~~^~~~~~~~~~~~~ user.cpp: In function ‘int main()’: user.cpp:32:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("cuplaj.in", "r", stdin); ^ user.cpp:33:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("cuplaj.out", "w", stdout); ^