Data update

Task/Burrows-Wheeler-transform/EasyLang/burrows-wheeler-transform.easy

@@ -0,0 +1,53 @@
+# stx$ = strchar 2
+# etx$ = strchar 3
+stx$ = "¹"
+etx$ = "²"
+#
+proc sort . d$[] .
+   for i = 2 to len d$[]
+      h$ = d$[i]
+      j = i - 1
+      while j >= 1 and strcmp h$ d$[j] < 1
+         d$[j + 1] = d$[j]
+         j -= 1
+      .
+      d$[j + 1] = h$
+   .
+.
+func$ bwt s$ .
+   ss$ = stx$ & s$ & etx$
+   for i to len ss$
+      a$ = substr ss$ 1 i
+      b$ = substr ss$ (i + 1) 9999
+      tbl$[] &= b$ & a$
+   .
+   sort tbl$[]
+   for s$ in tbl$[]
+      r$ &= substr s$ len s$ 1
+   .
+   return r$
+.
+func$ ibwt r$ .
+   le = len r$
+   for i to le
+      tbl$[] &= ""
+   .
+   for j to le
+      for i to le
+         tbl$[i] = substr r$ i 1 & tbl$[i]
+      .
+      sort tbl$[]
+   .
+   for row$ in tbl$[]
+      if substr row$ le 1 = etx$
+         return substr row$ 2 (le - 2)
+      .
+   .
+.
+for s$ in [ "banana" "appellee" "dogwood" "TO BE OR NOT TO BE OR WANT TO BE OR NOT?" "SIX.MIXED.PIXIES.SIFT.SIXTY.PIXIE.DUST.BOXES" ]
+   print s$
+   h$ = bwt s$
+   print h$
+   print ibwt h$
+   print ""
+.