Initial data commit

Task/ABC-problem/Forth/abc-problem.fth

@@ -0,0 +1,30 @@
+: blockslist s" BOXKDQCPNAGTRETGQDFSJWHUVIANOBERFSLYPCZM" ;
+variable blocks
+: allotblocks ( -- ) here blockslist dup allot here over - swap move blocks ! ;
+: freeblocks blockslist nip negate allot ;
+: toupper 223 and ;
+
+: clearblock ( addr-block -- )
+dup '_' swap c!
+dup blocks @ - 1 and if 1- else 1+ then
+'_' swap c!
+;
+
+: pickblock ( addr-input -- addr-input+1 f )
+dup 1+ swap c@ toupper    ( -- addr-input+1 c )
+blockslist nip 0 do
+  blocks @ i + dup c@ 2 pick       ( -- addr-input+1 c addri ci c )
+  = if clearblock drop true unloop exit else drop then
+loop drop false
+;
+
+: abc ( addr-input u -- f )
+allotblocks
+0 do
+  pickblock
+  invert if drop false unloop exit cr then
+loop drop true
+freeblocks
+;
+
+: .abc abc if ." True" else ." False" then ;