Compilare: user.cpp: In function ‘int main()’: user.cpp:23:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<s.size();i++) ^ user.cpp:11:26: warning: unused variable ‘l’ [-Wunused-variable] int i,j,xx,nr,ok,n,x,l,p,nrr; ^ user.cpp:11:28: warning: unused variable ‘p’ [-Wunused-variable] int i,j,xx,nr,ok,n,x,l,p,nrr; ^ user.cpp:55:22: warning: ‘op’ may be used uninitialized in this function [-Wmaybe-uninitialized] if(op=='-') ^