Compilare: main.cpp: In function 'void solve_queries()': main.cpp:243:9: warning: unused variable 't' [-Wunused-variable] int t=1,_val; ^ main.cpp:243:13: warning: unused variable '_val' [-Wunused-variable] int t=1,_val; ^~~~ main.cpp: In member function 'char Ifstream::read_ch()': main.cpp:18:36: 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,DIM,fin); ^