Compilare: user.cpp: In function ‘long long int sum(long long int, long long int)’: user.cpp:31:23: warning: iteration 28u invokes undefined behavior [-Waggressive-loop-optimizations] ans += p2mod[k]*sum(L,C,k); ^ user.cpp:30:28: note: containing loop for(long long k = 0; k <= BIT_MAX; k++) ^ user.cpp: In function ‘int main()’: user.cpp:52:77: warning: iteration 27u invokes undefined behavior [-Waggressive-loop-optimizations] p2mod[i] = (p2mod[i-1]*2 >= MOD) ? p2mod[i-1]*2 - MOD : p2mod[i-1]*2; ^ user.cpp:49:22: note: containing loop for(int i = 1; i <= 31; i++) ^