Update 357-count-numbers-with-unique-digits.js

Author: everthis

357-count-numbers-with-unique-digits.js

@@ -1,3 +1,23 @@
+/**
+ * @param {number} n
+ * @return {number}
+ */
+const countNumbersWithUniqueDigits = function(n) {
+  if(n === 0) return 1
+  let res = 10
+  let uniqueDigits = 9, avail = 9
+  while(n > 1 && avail) {
+    uniqueDigits = uniqueDigits * avail
+    res += uniqueDigits
+    avail--
+    n--
+  }
+  
+  return res
+};
+
+// another
+
 /**
  * @param {number} n
  * @return {number}