Compilare: user.cpp: In function ‘int main()’: user.cpp:67:23: warning: operation on ‘q’ may be undefined [-Wsequence-point] c[--q]+=c[q+1]; ^ user.cpp:72:23: warning: operation on ‘q’ may be undefined [-Wsequence-point] c[--q]-=c[q+1]; ^ user.cpp:76:23: warning: operation on ‘q’ may be undefined [-Wsequence-point] c[--q]*=c[q+1]; ^ user.cpp:81:23: warning: operation on ‘q’ may be undefined [-Wsequence-point] c[--q]/=c[q+1]; ^