Compilare: user.cpp: In function ‘bool cmp(re, re)’: user.cpp:14:29: warning: NULL used in arithmetic [-Wpointer-arith] return (strcmp(i.n,j.n)<NULL); ^ user.cpp: In function ‘int main()’: user.cpp:24:58: warning: NULL used in arithmetic [-Wpointer-arith] if(strcmp(ccv,v[i].n)==NULL){v[i].c+=ct;gs=1;break;} ^ user.cpp:39:48: warning: NULL used in arithmetic [-Wpointer-arith] if(strcmp(ccv,v[j].n)==NULL){v[j].c+=ct;gs=1;break;} ^