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module qsort_c_module
implicit none
public :: QsortC
private :: Partition
contains
recursive subroutine QsortC(A,B)
real, intent(in out), dimension(:) :: A
real, intent(in out), dimension(:,:) :: B
integer :: iq
if(size(A) > 1) then
call Partition(A, iq, B)
call QsortC(A(:iq-1),B(:,:iq-1))
call QsortC(A(iq:),B(:,iq:))
endif
end subroutine QsortC
subroutine Partition(A, marker, B)
real, intent(in out), dimension(:) :: A
real, intent(in out), dimension(:,:) :: B
integer, intent(out) :: marker
integer :: i, j
real :: temp
real ,dimension(1:size(A))::temb
real :: x ! pivot poin
x = A(1)
i= 0
j= size(A) + 1
do
j = j-1
do
if (A(j) <= x) exit
j = j-1
end do
i = i+1
do
if (A(i) >= x) exit
i = i+1
end do
if (i < j) then
! exchange A(i) and A(j)
temp = A(i)
temb = B(:,i)
A(i) = A(j)
B(:,i)=B(:,j)
A(j) = temp
B(:,j)=temb
elseif (i == j) then
marker = i+1
return
else
marker = i
return
endif
end do
end subroutine Partition
end module qsort_c_module
program www_fcode_cn
use qsort_c_module
implicit none
integer, parameter :: r = 3
real, dimension(1:r) :: myarray = (/0, 50, 20/)
real, dimension(1:r,1:r) :: mb=(/1,2,3,4,5,6,7,8,9/)
write(2,*) "原数组:", myarray
write(2,'*') "原数组:", mb
call QsortC(myarray,mb)
write(2,*) "排序后:", myarray
write(2,'*') "排序后:", mb
end program www_fcode_cn
用这个修改后的快速排序法,排列特征值A,和特征向量B,出现了错误:
B排序输出后,出现了这样的数字:1.000000 2.000000 3.000000 7.000000
8.000000 9.000000 4.000000 5.000000 -1.5823616E-26
请问是哪里出错了,非常感谢
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