Compilare: user.cpp: In function ‘int query(int, int, int, int)’: user.cpp:85:33: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<lazy[nod].size();i++){ ^ user.cpp:96:33: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<lazy[nod].size();i++){ ^ user.cpp: In function ‘char nextch()’: user.cpp:13:31: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread(buf,1,MAXBUF,fi); ^