! 散列查找法范例
! by perng 1997/8/31
program hashing_search_demo
  implicit none
  integer, parameter :: n=10 ! 類型的大小
  integer source(n) ! 存放數據組的類型
  integer a(n)      ! 存放hashing 后的類型
  integer key               ! 記錄所要找的值
  integer i                 ! 循環記數器
  integer loc
  data source /21,53,71,19,61,81,3,17,44,93/
  integer hash
  hash(key) = key/10+1 ! 定義hash函數

  write(*,"('source=>',10I3)") source
  
  a=0
  do i=1,n
    loc = hash( source(i) )
    do while(.true.)
	  if ( a(loc)==0 ) then
	    a(loc)=i
		exit
	  else
	    loc=loc+1
		if ( loc>n ) loc=1
	  end if
	end do
  end do

  write(*,*) 'input key:'
  read (*,*) key

  loc = hash(key)
  do i=1,N
	if ( a(loc)==0 ) then
	  write(*,*) "Not found."
	  exit
	else if ( source( a(loc) )==KEY ) then
	  write(*,"('Source(',I2,' )=',I3)") a(loc), key
	  exit
	else
	  loc=loc+1
	  if ( loc>n ) loc=1
	end if
  end do
  if ( i>N ) write(*,*) "Not found."

  stop
end program