Data commit

Task/Mertens-function/BCPL/mertens-function.bcpl

@@ -0,0 +1,36 @@
+get "libhdr"
+
+manifest $( limit = 1000 $)
+
+let mertens(v, max) be
+$(  v!1 := 1
+    for n = 2 to max do
+    $(  v!n := 1
+        for k = 2 to n do
+            v!n := v!n - v!(n/k)
+    $)
+$)
+
+let start() be
+$(  let m = vec limit
+    let eqz, crossz = 0, 0
+
+    writes("The first 99 Mertens numbers are:*N")
+    mertens(m, limit)
+    for y=0 to 90 by 10 do
+    $(  for x=0 to 9 do
+            test x+y=0
+                then writes("   ")
+                else writed(m!(x+y),3)
+        wrch('*N')
+    $)
+
+    for x=2 to limit do
+        if m!x=0 then
+        $(  eqz := eqz + 1
+            unless m!(x-1)=0 do crossz := crossz + 1
+        $)
+
+    writef("M(N) is zero %N times.*N", eqz)
+    writef("M(N) crosses zero %N times.*N", crossz)
+$)