一个数的每一位数相加,所得的和能被3整除的话,那么这个数就可以被3整除。 (这个定理没学过?) example: ex_1:57; because 5+7=12; 12 mod 3 =0; so 57 mod 3 =0. ex_2:183; because 1+8+3=12; 12 mod 3 =0; so 183 mod 3 =0. ex_3:1826; because 1+8+2+6=17; 17 mod 3 <>0; so 1826 mod 3 <>0. ex_4:1926; because 1+9+2+6=18; 18 mod 3 =0; so 1926 mod 3 =0.
var s:string; h,i:longint; begin readln(s); h:=0; for i:=1 to length(s) do begin h:=(ord(s[i])-48)+h; end; if h mod 3=0 then writeln('Good') else writeln('Bad'); readln;readln; end. 可以吗!?