Compilare: user.cpp: In function ‘long long unsigned int POW(int, int)’: user.cpp:31:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(ull i = 1; i <= y; i <<= 1) ^ user.cpp: In function ‘void read()’: user.cpp:13:20: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &n); ^ user.cpp: In function ‘void write()’: user.cpp:74:31: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &a, &b); ^