Data update

Task/Van-der-Corput-sequence/EasyLang/van-der-corput-sequence.easy

@@ -1,18 +1,17 @@
-proc vdc b n . v .
+func vdc b n .
    s = 1
-   v = 0
    while n > 0
       s *= b
       m = n mod b
       v += m / s
       n = n div b
    .
+   return v
 .
 for b = 2 to 5
    write "base " & b & ":"
    for n range0 10
-      call vdc b n v
-      write " " & v
+      write " " & vdc b n
    .
    print ""
 .

Task/Van-der-Corput-sequence/Lua/van-der-corput-sequence-2.lua

@@ -0,0 +1,27 @@
+function vdc( nth, base ) -- returns the numerator & denominator of the sequence element n in base
+    local p, q, n = 0, 1, nth
+    while n ~= 0 do
+        p = p * base
+        p = p + n % base;
+        q = q * base;
+        n = math.floor( n / base )
+    end
+    local num, denom = p, q;
+    -- reduce the numerator and denominator by their gcd
+    while p ~= 0 do
+        n = p
+        p = q % p
+        q = n
+    end
+    num   = math.floor( num   / q )
+    denom = math.floor( denom / q )
+    return num, denom
+end
+for b = 2,5 do
+    io.write( "base ", b, ": " )
+    for n = 0,9 do
+        local num, denom = vdc( n, b )
+        io.write( " ", num ) if num ~= 0 then io.write( "/", denom ) end
+    end
+    io.write( "\n" )
+end