0010/* PBINSEAR
0020/* Quick search in a sorted array
0030/* Klaus-Peter Plog
0040/*
0050DEFINE DATA LOCAL
0060/*----------------------------------------------------- Array definition
00701 #ARRAY-COUNT(I2) INIT <10>
00801 #ARRAY(A2/10) INIT <'00','03','07','10','11','12','14','20','22','28'>
0090/*------------------------------------------------ That, what you search
01001 #SEARCH(A2)
0110/*--------------------------------------------- Variables of the routine
01201 #BEG(I2)
01301 #END(I2)
01401 #P(I2)
01501 #EXIT(L)
01601 #FOUND(L)
0170/*----------------------------------------------------------------------
0180END-DEFINE
0190/*
0200ASSIGN #SEARCH = '20'
0210PERFORM BINARY-SEARCH
0220IF #FOUND
0230  WRITE #SEARCH 'found at position' #P 
0240ELSE
0250  WRITE #SEARCH 'not found'
0260END-IF
0270/*
0280DEFINE SUBROUTINE BINARY-SEARCH /*======================================
0290RESET #EXIT #FOUND
0300ASSIGN #BEG = 1
0310ASSIGN #END = #ARRAY-COUNT
0320REPEAT WHILE NOT #EXIT
0330  COMPUTE #P = (#END - #BEG) / 2 + #BEG
0340  DECIDE FOR FIRST CONDITION
0350    WHEN #SEARCH > #ARRAY(#P)   COMPUTE #BEG = #P + 1
0360    WHEN #SEARCH < #ARRAY(#P)   COMPUTE #END = #P - 1
0370    WHEN #SEARCH = #ARRAY(#P)   ASSIGN #FOUND = #EXIT = TRUE
0380    WHEN NONE IGNORE
0390  END-DECIDE
0400  IF NOT #FOUND AND (#P = #END OR = #BEG)
0410    ASSIGN #EXIT = TRUE
0420  END-IF
0430END-REPEAT
0440END-SUBROUTINE /*=======================================================
0450END