Compilare: main.cpp: In function 'int main()': main.cpp:123:21: warning: unused variable 'x' [-Wunused-variable] for(int x:v[i]) ^ main.cpp: In member function 'char input_parser::next()': main.cpp:47:65: warning: ignoring return value of 'size_t fread(void*, size_t, size_t, FILE*)', declared with attribute warn_unused_result [-Wunused-result] fread(this->buffer,1,max_load,this->fin),this->pos=0; ^ main.cpp: In function 'int main()': main.cpp:134:15: warning: 'sol' may be used uninitialized in this function [-Wmaybe-uninitialized] out<<sol<<" "<<sum; ^~~