Data commit

Task/Negative-base-numbers/Ring/negative-base-numbers.ring

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+# Project : Negative base numbers
+
+negs = [[146,-3],[21102,-3],[10,-2],[11110,-2],[15,-10],[195,-10]]
+for n = 1 to len(negs) step 2
+     enc = encodeNegBase(negs[n][1],negs[n][2])
+     encstr = showarray(enc)
+     dec = decodeNegBase(negs[n+1][1],negs[n+1][2])
+     see "" + negs[n][1] + " encoded in base " + negs[n][2] + " = " + encstr + nl
+     see "" + negs[n+1][1] + " decoded in base " + negs[n+1][2] + " = " + dec + nl
+next
+
+func encodeNegBase(n,b)
+       out = []
+       while n != 0
+               rem = (n%b)
+               if rem < 0
+                  rem = rem - b
+               ok
+               n = ceil(n/b)
+               rem = fabs(rem)
+               add(out,rem)
+       end
+       out = reverse(out)
+       return out
+
+func decodeNegBase(n,b)
+        out = 0
+        n = string(n)
+        for nr = len(n) to 1 step -1
+             out = out + n[nr]*pow(b,len(n)-nr)
+        next
+        return out
+
+func showarray(vect)
+        svect = ""
+        for n = 1 to len(vect)
+              svect = svect + vect[n]
+        next
+        return svect