Compilare: main.cpp: In function 'bool evalNot()': main.cpp:55:35: warning: array subscript has type 'char' [-Wchar-subscripts] const bool crt = vals[a[poz++]]; ^ main.cpp: In function 'int main()': main.cpp:66:33: warning: array subscript has type 'char' [-Wchar-subscripts] scanf(" %c", &x), vals[x] ^= 1, ^ main.cpp:61:35: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("bool.in", "r", stdin); ^ main.cpp:62:37: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("bool.out", "w", stdout); ^ main.cpp:67:29: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] printf("%d", eval()); ^