Compilare: user.cpp: In function ‘int nextInt()’: user.cpp:39:24: warning: array subscript has type ‘char’ [-Wchar-subscripts] for (; !isDigit[*head]; ++head); ^ user.cpp:40:23: warning: array subscript has type ‘char’ [-Wchar-subscripts] for (; isDigit[*head]; ++head) ^ user.cpp: In function ‘int main()’: user.cpp:78:17: warning: NULL used in arithmetic [-Wpointer-arith] if (G[i] == NULL || impar[i]) { ^~~~