找到副程式如下
(來源：https://gist.github.com/t-nissie/479f0f16966925fa29ea)
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recursive subroutine quicksort(a, first, last)
implicit none
real*8 a(*), x, t
integer first, last
integer i, j
x = a( (first+last) / 2 )
i = first
j = last
do
do while (a(i) < x)
i=i+1
end do
do while (x < a(j))
j=j-1
end do
if (i >= j) exit
t = a(i); a(i) = a(j); a(j) = t
i=i+1
j=j-1
end do
if (first < i-1) call quicksort(a, first, i-1)
if (j+1 < last) call quicksort(a, j+1, last)
end subroutine quicksort
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自己試寫了一下主程式如下
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program quick_sort_test
real*8 a(*)
integer first, last
data a/12.0,54.0,65.0,2.0,3.0,40.0,91.0,7.0,321.0,50.0/
first=0
last=22
call quicksort(a, first, last)
end program
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因為不太懂
1. real*8 a(*) 的星號
2. first, last 的意義
結果一直顯示array boundary有問題
調了 first 和 last 也還是一樣
主程式應該要怎麼修改呢?
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