Compilare: user.cpp: In function ‘int main()’: user.cpp:49:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=1; i<= t; i++) ^ user.cpp:66:21: warning: unused variable ‘r’ [-Wunused-variable] unsigned long long r , t , y; ^ user.cpp:66:25: warning: unused variable ‘t’ [-Wunused-variable] unsigned long long r , t , y; ^ user.cpp:66:29: warning: unused variable ‘y’ [-Wunused-variable] unsigned long long r , t , y; ^