Compilare: user.cpp: In function ‘int main()’: user.cpp:10:12: warning: right operand of comma operator has no effect [-Wunused-value] in>>n,k; ^ user.cpp:12:19: warning: ‘k’ may be used uninitialized in this function [-Wmaybe-uninitialized] suma = ((n%k)*((n+1)%k)*((n-1)%k)/3 ); ^