Compilare: user.cpp: In function ‘int main()’: user.cpp:29:28: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j=0;j<lin.size();j++) ^ user.cpp:19:13: warning: unused variable ‘k’ [-Wunused-variable] int i,j,k; ^ user.cpp:16:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("cerc3.in","r",stdin); ^ user.cpp:17:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("cerc3.out","w",stdout); ^