rem 生成指定１００內的質數陣列
function primenumber()
dim a_prime as variant
a_prime = primenumberformax(100)
primenumber = a_prime
end function
rem 生成指定範圍內的質數陣列
function primenumberformax(byval maxnum as integer) as integer()
redim a_prime_tmp(maxnum) as integer
dim i_count as integer
a_prime_tmp(i_count) = 2
dim i as integer, j as integer
for i = 2 to maxnum
for j = 2 to int(sqr(i)) + 1
if i mod j = 0 then
exit for
elseif j = int(sqr(i)) + 1 then
i_count = i_count + 1
a_prime_tmp(i_count) = i
end if
next
next
redim a_prime(i_count) as integer
for i = 0 to i_count
a_prime(i) = a_prime_tmp(i)
next
primenumberformax = a_prime
end function
rem "獲取陣列長度"
public function arraylength(byval ary) as integer
on error resume next
arraylength = ubound(ary) - lbound(ary) + 1
end function
rem 判斷陣列為空
public function arrayisnull(arr) as boolean
dim i&
on error resume next
i = ubound(arr)
if err = 0 then arrayisnull = true
end function
rem 判斷是否質數
function isprime(byval num as integer) as boolean
dim a_prime as variant
a_prime = primenumberformax(num + 1)
dim i_len as integer
i_len = arraylength(a_prime)
dim i as integer
dim i_tmp as integer
for i = i_len - 1 to 0 step -1
i_tmp = a_prime(i)
if i_tmp = num then
isprime = true
exit for
end if
if i_tmp < num then
isprime = false
exit for
end if
next
end function
rem "分解質因數，獲取質數陣列"
function primefactor(byval num as integer) as integer()
dim reprimfactor() as integer
'判斷不是乙個質數
if isprime(num) then
dim renull() as integer
redim preserve renull(0 to 0) as integer
primefactor = renull
else
'如果不是,則生成乙個比它小一半的質數陣列,對它進行測試
dim halfnum as integer
halfnum = num + 1
'質數陣列
dim a_prime as variant
a_prime = primenumberformax(halfnum)
'返回陣列
dim primfactor as variant
'陣列索引
dim index as integer
index = 0
'對a_prime遍歷,遍歷要放到遞迴函式中,否則演算法效率不高
'再建立乙個函式對陣列進行遞迴
primfactor = getprimefactor(index, a_prime, num)
'整理返回值,去年為0的值
index = 0
for each primf in primfactor
if primf > 0 then
redim preserve reprimfactor(0 to index) as integer
reprimfactor(index) = primfactor(index)
index = index + 1
end if
next
'返回物件primfactor
primefactor = reprimfactor
end if
end function
rem 建立乙個函式對陣列進行遞迴,獲取質因子陣列
rem 質因子陣列則小到大排列
function getprimefactor(byval index as integer, byval a_prim, byval num as integer) as integer()
'本函式中不新增num本身,以免重複
'定義乙個臨時陣列
dim tmp_arr() as integer
redim preserve tmp_arr(0 to 1) as integer
'定義乙個質數
dim prim as integer
'從陣列中按索引index取出這個質數
prim = a_prim(index)
'取模判斷
if num mod prim = 0 then '能被整除,則求商
'求商quotien
dim i_quot as integer
i_quot = num / prim
tmp_arr(0) = prim
'商不為1
if i_quot > 1 then '這個條件是防止商為0
dim a_tmp as variant
a_tmp = getprimefactor(index, a_prim, i_quot)
dim a_len_new as integer
a_len_new = arraylength(a_tmp)
if a_len_new > 0 then
redim preserve tmp_arr(0 to a_len_new) as integer
dim i as integer
i = 1
for each tmp in a_tmp
if (a_tmp(i - 1) > 0) then
tmp_arr(i) = a_tmp(i - 1)
i = i + 1
end if
next
end if
end if
else '不能被整除,則測試下乙個質數
index = index + 1
prim = a_prim(index)
tmp_arr = getprimefactor(index, a_prim, num)
end if
getprimefactor = tmp_arr
end function
function test()
dim n as integer
n = 999
dim a_test as variant
a_test = primefactor(n)
for each i_n in a_test
debug.print " 質因子: " & i_n
next
end function
質因數的個數
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質因數的個數
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質因數的個數
求正整數n n 1 的質因數的個數。相同的質因數需要重複計算。如120 2 2 2 3 5，共有5個質因數。輸入描述 可能有多組測試資料，每組測試資料的輸入是乙個正整數n，1 輸出描述 對於每組資料，輸出n的質因數的個數。示例1 1205import math def judge num 判斷是否是...