Compilare: user.cpp: In function ‘int main()’: user.cpp:45:30: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread(buff,1,20000,stdin); ^ user.cpp: In function ‘void read(int&)’: user.cpp:12:103: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] while(buff[pos] < '0' || buff[pos] > '9') if(++pos == 20000) fread(buff, 1, 20000, stdin), pos = 0; ^ user.cpp:17:65: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] if(++pos == 20000) fread(buff, 1, 20000, stdin), pos = 0; ^ user.cpp: In function ‘void solve(int, int)’: user.cpp:37:5: warning: assuming signed overflow does not occur when assuming that (X + c) >= X is always true [-Wstrict-overflow] if(pm>inc) ^