Compilare: user.cpp: In function ‘void ciur(long long unsigned int)’: user.cpp:16:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i = 3; i <= n; i += 2) { ^ user.cpp:19:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (j = i + i + i; j <= n; j += i << 1) { ^ user.cpp:22:13: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(i>=a){ ^ user.cpp: In function ‘int main()’: user.cpp:45:13: warning: unused variable ‘i’ [-Wunused-variable] int i,j,limit=2; ^ user.cpp:45:15: warning: unused variable ‘j’ [-Wunused-variable] int i,j,limit=2; ^ user.cpp:45:17: warning: unused variable ‘limit’ [-Wunused-variable] int i,j,limit=2; ^