Data update

Task/CUSIP/Pluto/cusip.pluto

@@ -0,0 +1,33 @@
+local function is_cusip(s)
+    if #s != 9 then return false end
+    local sum = 0
+    for i = 1, 8 do
+        local c = s[i]
+        local v = switch true do
+            case c >= '0' and c <= '9' -> c:byte() - 48
+            case c >= 'A' and c <= 'Z' -> c:byte() - 55
+            case c == "*" -> 36
+            case c == "@" -> 37
+            case c == "#" -> 38
+            default        -> nil
+        end
+        if !v then return false end
+        if i % 2 == 0 then v = v * 2 end  -- check if even as using 1-based indexing
+        sum += v // 10 + v % 10
+    end
+    return s[9]:byte() - 48 == (10 - (sum % 10)) % 10
+end
+
+local candidates = {
+    "037833100",
+    "17275R102",
+    "38259P508",
+    "594918104",
+    "68389X106",
+    "68389X105"
+}
+
+for candidates as candidate do
+    local b = is_cusip(candidate) ? "correct" : "incorrect"
+    print($"{candidate} -> {b}")
+end