Add 357_Count_Numbers_with_Unique_Digits.java

Author: Sean Prashad

Dynamic Programming/357_Count_Numbers_with_Unique_Digits.java

@@ -0,0 +1,16 @@
+class Solution {
+    public int countNumbersWithUniqueDigits(int n) {
+        if (n == 0) {
+            return 1;
+        }
+
+        int result = 10, base = 9;
+
+        for (int i = 2; i <= n && i <= 10; i++) {
+            base = base * (9 - i + 2);
+            result += base;
+        }
+
+        return result;
+    }
+}