Compilare: user.cpp: In function ‘int euclid(long long int, long long int, long long int&, long long int&)’: user.cpp:19:1: warning: no return statement in function returning non-void [-Wreturn-type] } ^ user.cpp: In function ‘int main()’: user.cpp:23:22: warning: unused variable ‘c’ [-Wunused-variable] long long int a,b,c,x,y; ^