Question

车牌00000到99999连续100000个5位正整数中,各位数字和是9的倍数且各位数字中至少出现一次9,有多少这样牌

Answer 1

一共有4551个这样的车牌.

把下面这个程序在FoxPro中执行就都出来了.

* -----------------

SET TALK OFF

j=0

FOR i=0 TO 99999

a=PADL(ALLTRIM(STR(i,5,0)),5,"0")

IF( AT("9",a)0 )

a1=VAL(SUBSTR(a,1,1))

a2=VAL(SUBSTR(a,2,1))

a3=VAL(SUBSTR(a,3,1))

a4=VAL(SUBSTR(a,4,1))

a5=VAL(SUBSTR(a,5,1))

b=a1+a2+a3+a4+a5

IF( (b%9)=0 )

j=j+1

" "+a+" "

ENDIF

ENDIF

ENDFOR

* ------------

如：00009 00090 00099 00189 00198 00279 00297 00369 00396

00459 00495 00549 00594 00639 00693 00729 .99999