Compilare: user.cpp: In function ‘int main()’: user.cpp:109:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j=0; j<v[i].size(); ++j) { ^ user.cpp: In function ‘char getChar()’: user.cpp:53:52: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] if(pos == BUF) pos = 0, fread(buf, 1, BUF, fin); ^