sorting

[acharls]

Hi all,

I have a sorting program

do i=1,4
do j=i+1,5
if(er(i).gt.er(j))then
temp=er(i)
er(i)=er(j)
er(j)=temp
end if
end do
end do

I am looking how I can print sorted values with their array index as in original data.

example
er=[9,3,2,5,1,4]
sorted er=[1,2,3,4,5,9] & print original index of elements
ie 5,3,2,6,4,1 while printing the sorted output.

Thanks in advance

Charls Antony

 

[salgerman]

what you can do is put together another "index" array of the same size N as the array you want to sort, fill it in with the numbers 1 through N and, THEN, every time you do a swap in the sorted array, you make the same swap in the "index" array.

 

[xwb]

Use a type.

type (Pair)
   integer value ! er values
   integer index
end type

When initializing your array of Pair. Assume that PMAX is the size

do ii = 1, PMAX
   plist(ii)%index = ii
   plist(ii)%value = ??   ! how er(ii) got its value
end do

When sorting, the comparison is

if (plist(ii).value .lt. plist(jj).value) then ...