Compilare: user.cpp: In member function ‘void Ecuation::read_ec()’: user.cpp:60:39: warning: array subscript has type ‘char’ [-Wchar-subscripts] if (ord[work.top()] < ord[ s[pos] ]) break; ^ user.cpp:60:55: warning: array subscript has type ‘char’ [-Wchar-subscripts] if (ord[work.top()] < ord[ s[pos] ]) break; ^ user.cpp: In member function ‘bool Ecuation::check(int*)’: user.cpp:83:33: warning: array subscript has type ‘char’ [-Wchar-subscripts] comp.push(vars[e]); ^ user.cpp: In function ‘int main()’: user.cpp:142:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("sistem2.in","r",stdin); ^ user.cpp:143:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("sistem2.out","w",stdout); ^ user.cpp:145:28: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d\n", &n, &m); ^ user.cpp: In member function ‘void Ecuation::read_ec()’: user.cpp:43:20: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets(s + 1); ^ /tmp/ccYAXmNp.o: In function `main': user.cpp:(.text.startup+0xdf): warning: the `gets' function is dangerous and should not be used.