Compilare: user.cpp: In function ‘int main()’: user.cpp:131:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while (iy < ly.size() && in < ln.size()) ^ user.cpp:131:43: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while (iy < ly.size() && in < ln.size()) ^ user.cpp:135:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while (iy < ly.size()) ^ user.cpp:138:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while (in < ln.size()) ^ user.cpp: In function ‘int readInt()’: user.cpp:35:40: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread(buffer,1,BSIZE,stdin); ^ user.cpp:46:40: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread(buffer,1,BSIZE,stdin); ^ user.cpp: In function ‘int main()’: user.cpp:75:29: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("luff.in","r",stdin); ^ user.cpp:76:31: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("luff.out","w",stdout); ^ user.cpp:78:28: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread(buffer,1,BSIZE,stdin); ^