以下 程序的 功能 是判断输入字符种类 。填空完成程序 。 #include
void main() { char c; printf("Enter a character:"); ___________________ ; if(c<0x20) printf("This is a control character\n"); else if( ___________________ ) printf("This is a digit\n"); else if( ___________________ ) printf("This is a upper letter\n"); else if(c>='a'&&c<='z') printf("This is a lower letter\n"); else printf("This is other character\n"); }