Data commit

Task/CUSIP/Java/cusip.java

@@ -0,0 +1,39 @@
+import java.util.List;
+
+public class Cusip {
+    private static Boolean isCusip(String s) {
+        if (s.length() != 9) return false;
+        int sum = 0;
+        for (int i = 0; i <= 7; i++) {
+            char c = s.charAt(i);
+
+            int v;
+            if (c >= '0' && c <= '9') {
+                v = c - 48;
+            } else if (c >= 'A' && c <= 'Z') {
+                v = c - 55;  // lower case letters apparently invalid
+            } else if (c == '*') {
+                v = 36;
+            } else if (c == '@') {
+                v = 37;
+            } else if (c == '#') {
+                v = 38;
+            } else {
+                return false;
+            }
+            if (i % 2 == 1) v *= 2;  // check if odd as using 0-based indexing
+            sum += v / 10 + v % 10;
+        }
+        return s.charAt(8) - 48 == (10 - (sum % 10)) % 10;
+    }
+
+    public static void main(String[] args) {
+        List<String> candidates = List.of(
+                "037833100", "17275R102", "38259P508", "594918104", "68389X106", "68389X105", "EXTRACRD8",
+                "EXTRACRD9", "BADCUSIP!", "683&9X106", "68389x105", "683$9X106", "68389}105", "87264ABE4"
+        );
+        for (String candidate : candidates) {
+            System.out.printf("%s -> %s%n", candidate, isCusip(candidate) ? "correct" : "incorrect");
+        }
+    }
+}