// efg, April 1998

FUNCTION MedianInteger (x:  ARRAY OF INTEGER):  INTEGER;
  VAR
    i        :  INTEGER;
    j        :  INTEGER;
    Middle   :  INTEGER;
    Temporary:  INTEGER;
BEGIN
  // Use truncated selection sort to find median

  Middle := (High(x)+1) DIV 2;

  FOR i := 0 TO Middle DO
  BEGIN
    FOR j := 1 TO High(x)-i DO
    BEGIN
      IF   x[j] > x[j-1]
      THEN BEGIN
        Temporary := x[j];
        x[j] := x[j-1];
        x[j-1] := Temporary
      END
    END

  END;

  IF   Odd(High(x))   // range is 0 to High(x) ==> High(x) + 1 elements
  THEN BEGIN
    // When High(x) is Odd, there are an even number of elements in array.
    // Define median as average of two middle values.
    RESULT := (x[middle] + x[middle-1]) DIV 2
  END
  ELSE BEGIN
    // When High(x) is Even, there are an odd number of elements in array.
    // Median is the middle value.
    RESULT := x[middle]
  END
END {MedianInteger};