Compilare: user.cpp: In function ‘int query(int, long long int)’: user.cpp:140:8: warning: unused variable ‘nv’ [-Wunused-variable] ll nv = -1; ^ user.cpp: In member function ‘char InParser::read_ch()’: user.cpp:15:38: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread(buff, 1, 4096, fin); ^ user.cpp: In function ‘int next(int, long long int, int)’: user.cpp:135:19: warning: ‘best’ may be used uninitialized in this function [-Wmaybe-uninitialized] return best + 1; ^ user.cpp: In function ‘int query(int, long long int)’: user.cpp:135:19: warning: ‘best’ may be used uninitialized in this function [-Wmaybe-uninitialized] user.cpp:128:26: note: ‘best’ was declared here int s = i, d = k, m, best; ^