YAPC::EU 2018 Glasgow Update!

Task/Pi/BASIC/pi-1.basic

@@ -0,0 +1,59 @@
+cls
+
+n   =1000
+len = 10*n \ 4
+needdecimal = true
+dim a(len)
+nines = 0
+predigit = 0	# {First predigit is a 0}
+
+for j = 1 to len
+   a[j-1] = 2	# {Start with 2s}
+next j
+
+for j = 1 to n
+   q = 0
+   for i = len to 1 step -1
+      #  {Work backwards}
+      x   = 10*a[i-1] + q*i
+      a[i-1] = x % (2*i - 1)
+      q    = x \ (2*i - 1)
+   next i
+   a[0] = q % 10
+   q = q \ 10
+   if q = 9 then
+      nines = nines + 1
+   else
+      if q = 10 then
+         d = predigit+1: gosub outputd
+         if nines > 0 then
+            for k = 1 to nines
+               d =  0: gosub outputd
+            next k
+         end if
+         predigit = 0
+         nines = 0
+      else
+         d = predigit: gosub outputd
+         predigit = q
+         if nines <> 0 then
+            for k = 1 to nines
+               d =  9: gosub outputd
+            next k
+            nines = 0
+         end if
+      end if
+   end if
+next j
+print predigit
+end
+
+outputd:
+if needdecimal then
+   if d = 0 then return
+   print d + ".";
+   needdecimal = false
+else
+   print d;
+end if
+return