Compilare: main.cpp: In function 'int read_int()': main.cpp:49:35: warning: array subscript has type 'char' [-Wchar-subscripts] while(!isDigit[c = read_char()]); ^ main.cpp:51:20: warning: array subscript has type 'char' [-Wchar-subscripts] while(isDigit[c]) ^ main.cpp: In function 'char read_char()': main.cpp:22:54: warning: ignoring return value of 'size_t fread(void*, size_t, size_t, FILE*)', declared with attribute warn_unused_result [-Wunused-result] fread(buffer, sizeof(char), BUFFER_SIZE, fin); ^