Compilare: user.cpp: In function ‘int andl()’: user.cpp:53:23: warning: array subscript has type ‘char’ [-Wchar-subscripts] retval = val[tok[sp]]; ^ user.cpp: In function ‘int main()’: user.cpp:117:11: warning: array subscript has type ‘char’ [-Wchar-subscripts] val[read] = 1 - val[read]; ^ user.cpp:117:27: warning: array subscript has type ‘char’ [-Wchar-subscripts] val[read] = 1 - val[read]; ^ user.cpp:69:21: warning: ignoring return value of ‘char* fgets(char*, int, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fgets(s, LMAX, fin); ^ user.cpp:112:23: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fin, "%d", &N); ^