Compilare: user.cpp: In function ‘int verif(int)’: user.cpp:14:13: warning: NULL used in arithmetic [-Wpointer-arith] for(;S[i]!=NULL && W-v[pto(S[i])]>=0;i++) W-=v[pto(S[i])]; ^ user.cpp:15:15: warning: NULL used in arithmetic [-Wpointer-arith] return S[i]==NULL; ^ user.cpp: In function ‘int main()’: user.cpp:23:19: warning: NULL used in arithmetic [-Wpointer-arith] for(i=0;S[i]!=NULL && W-v[pto(S[i])]>=0;i++){ ^ user.cpp:27:26: warning: NULL used in arithmetic [-Wpointer-arith] if(verif(i)) for(;S[i]!=NULL;i++) out<<S[i]; ^