FOCALCMS
Usage notes:
     
FOCALCMS uses normal CMS terminal input routines.  Some input characters cause
special handling.  You may need to pick different symbols for CHARDEL
and LINEND or set these OFF to disable some of the line editing.

    CP SET LINEDIT OFF
    CP TERMINAL ESCAPE OFF 

Sample scripts
==============

n-Queens
--------

01.10 c 8-Queens problem in Focal-8
01.20 c Hacked by Akira KIDA, SDI00379@niftyserve.or.jp

10.10 c main
10.20 s nQueen = 8
10.30 d 20
10.40 s Count = 0; s pend = 0
10.50 s n = 0; d 30
10.60 d 60
10.70 t %1.0, "Total ", Count, " answers", !
10.80 q

20.10 c initialize
20.20 f i = 0, nQueen - 1; s Pos(i) = 0; s Row(i) = 1
20.40 f i = 0, nQueen * 2 - 2; s Up(i) = 1
20.50 f i = 0, nQueen * 2 - 2; s Down(i - nQueen + 1) = 1
20.60 s k = 0
20.70 r

30.10 c generate(n)
30.20 c make sure to use individual control variables in each nest levels
30.30 f k(n) = 0, nQueen - 1; d 40
30.40 r

40.10 c generate(n) body
40.20 i (-(Row(k(n)) * Up(n + k(n)) * Down(n - k(n)))) 40.30; r
40.30 s Pos(n) = k(n)
40.40 i (n - nQueen + 1) 40.50; d 50; r
40.50 s Row(k(n)) = 0; s Up(n + k(n)) = 0; s Down(n - k(n)) = 0
40.60 s n = n + 1; d 30; s n = n - 1
40.70 s Down(n - k(n)) = 1; s Up(n + k(n)) = 1; s Row(k(n)) = 1
40.80 r

50.10 c answer
50.20 s Count = Count + 1; s pend = pend + 1
50.30 f i = 0, nQueen - 1; s ans(pend * nQueen + i) = Pos(i)
50.40 i (pend - 3) 50.50; d 60
50.50 r

60.10 c flush answer
60.20 i (-pend) 60.30; r
60.30 f a = 1, pend; t %1.0, "       Solution #", Count - pend + a, "     "
60.40 t !
60.50 f i = 0, nQueen - 1; d 70
60.60 t ! ; s pend = 0
60.70 r

70.10 c answer inner loop
70.20 f a = 1, pend; d 80
70.30 t !
70.40 r

80.10 t "       "
80.20 f j = 0, nQueen - 1; d 90
80.30 r

90.10 c answer print element
90.20 i (ans(a * nQueen + i) - j) 90.50, 90.30, 90.50
90.30 t " Q"
90.40 r
90.50 t " ."
90.60 r