Compilare: user.cpp: In function ‘int main()’: user.cpp:38:28: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j=0;j<lin.size();j++) ^ user.cpp:53:24: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<lin.size();i++) ^ user.cpp:28:13: warning: unused variable ‘k’ [-Wunused-variable] int i,j,k; ^ user.cpp:25:34: 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:26:36: 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); ^