H數(shù)是指:僅包含質(zhì)因子2,3,5,7的數(shù)。
【示例】2,3,4,5,6,7,8,9,10均為H數(shù);但11不是H數(shù),12是H數(shù),13不是H數(shù)......
簡(jiǎn)介所謂H數(shù)是指該數(shù)除1以外,最多只有2,3,5,7四種因子。如630是H數(shù),而22不是。1
判斷方法用FreeBASIC來實(shí)現(xiàn)H數(shù)的算法
DECLARE FUNCTION HNUM(X AS INTEGER) AS INTEGER
DIM AS INTEGER I,N,J
INPUT N
I=1 'H數(shù)
J=0 '第J個(gè)H數(shù)
DO
I=I+1
IF HNUM(I)=1 THEN J=J+1
LOOP WHILE J