sort2.f90 1.91 KB
Newer Older
 Matthias Langer committed Nov 28, 2012 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 ``````! From numerical recipes ! Change by A. Stohl: Use of integer instead of real values subroutine sort2(n,arr,brr) implicit none integer :: n integer :: arr(n),brr(n) integer,parameter :: m=7,nstack=50 integer :: i,ir,j,jstack,k,l,istack(nstack) integer :: a,b,temp jstack=0 l=1 ir=n 1 if(ir-l.lt.m)then do j=l+1,ir a=arr(j) b=brr(j) do i=j-1,1,-1 if(arr(i).le.a)goto 2 arr(i+1)=arr(i) brr(i+1)=brr(i) end do i=0 2 arr(i+1)=a brr(i+1)=b end do if(jstack.eq.0)return ir=istack(jstack) l=istack(jstack-1) jstack=jstack-2 else k=(l+ir)/2 temp=arr(k) arr(k)=arr(l+1) arr(l+1)=temp temp=brr(k) brr(k)=brr(l+1) brr(l+1)=temp if(arr(l+1).gt.arr(ir))then temp=arr(l+1) arr(l+1)=arr(ir) arr(ir)=temp temp=brr(l+1) brr(l+1)=brr(ir) brr(ir)=temp endif if(arr(l).gt.arr(ir))then temp=arr(l) arr(l)=arr(ir) arr(ir)=temp temp=brr(l) brr(l)=brr(ir) brr(ir)=temp endif if(arr(l+1).gt.arr(l))then temp=arr(l+1) arr(l+1)=arr(l) arr(l)=temp temp=brr(l+1) brr(l+1)=brr(l) brr(l)=temp endif i=l+1 j=ir a=arr(l) b=brr(l) 3 continue i=i+1 if(arr(i).lt.a)goto 3 4 continue j=j-1 if(arr(j).gt.a)goto 4 if(j.lt.i)goto 5 temp=arr(i) arr(i)=arr(j) arr(j)=temp temp=brr(i) brr(i)=brr(j) brr(j)=temp goto 3 5 arr(l)=arr(j) arr(j)=a brr(l)=brr(j) brr(j)=b jstack=jstack+2 if(jstack.gt.nstack) then print*, 'nstack too small in sort2' stop end if if(ir-i+1.ge.j-l)then istack(jstack)=ir istack(jstack-1)=i ir=j-1 else istack(jstack)=j-1 istack(jstack-1)=l l=i endif endif goto 1 end subroutine sort2 ! (C) Copr. 1986-92 Numerical Recipes Software us.``````