请教多机联合运算问题 - VFP论坛

DIMENSION aSum[8] DIMENSION a208[208] FOR n = 1 TO 1000 IF EMPTY(a208) DIMENSION a208[208] FOR ai = 1 TO 208 a208[ai] = ai ENDFOR ENDIF FOR i = 1 TO 8 aSum[i] = _Rand(@a208) ENDFOR IF (aSum[1]+aSum[2]+aSum[3]+aSum[4]+aSum[5]+aSum[6]+aSum[7]+aSum[8]) == 836 *ASORT(aSum) ? aSum[1], aSum[2], aSum[3], aSum[4], aSum[5], aSum[6], aSum[7], aSum[8] *EXIT ENDIF ENDFOR RETURN FUNCTION _Rand(a208) IF EMPTY(a208) RETURN 0 ENDIF LOCAL up, ai, ret up = ALEN(a208) - 1 ai = INT(up * RAND() + 1) ret = a208[ai] ADEL(a208, ai) IF up > 0 DIMENSION a208[up] ENDIF RETURN ret ENDFUNC

第 24 楼

得分:10

可以试一下随机取得所有的组合时 n 有多少?

程序代码：

CREATE CURSOR d208 (c208 C(32))
INDEX ON c208 TAG c208
DIMENSION aSum[8]
DIMENSION a208[208]

FOR n = 1 TO 100000
    IF EMPTY(a208)
        DIMENSION a208[208]
        FOR ai = 1 TO 208
            a208[ai] = ai
        ENDFOR
    ENDIF
    FOR i = 1 TO 8
        aSum[i] = _Rand(@a208)
    ENDFOR
    IF (aSum[1]+aSum[2]+aSum[3]+aSum[4]+aSum[5]+aSum[6]+aSum[7]+aSum[8]) == 836
        ASORT(aSum)
        s208 = PADL(aSum[1],4," ")+PADL(aSum[2],4," ")+PADL(aSum[3],4," ")+PADL(aSum[4],4," ");
             + PADL(aSum[5],4," ")+PADL(aSum[6],4," ")+PADL(aSum[7],4," ")+PADL(aSum[8],4," ")
        IF !SEEK(s208)
            INSERT INTO d208 VALUES (s208)
            *IF RECCOUNT() == 所有组合数
            *    EXIT
            *ENDIF
        ENDIF
        *? aSum[1], aSum[2], aSum[3], aSum[4], aSum[5], aSum[6], aSum[7], aSum[8]
        *EXIT
    ENDIF
ENDFOR
GO TOP 
BROWSE
RETURN

FUNCTION _Rand(a208)
    IF EMPTY(a208)
        RETURN 0
    ENDIF
    LOCAL up, ai, ret
    up = ALEN(a208) - 1
    ai = INT(up * RAND() + 1)
    ret = a208[ai]
    ADEL(a208, ai)
    IF up > 0
        DIMENSION a208[up]
    ENDIF
    RETURN ret
ENDFUNC