Update 902-numbers-at-most-n-given-digit-set.js

Author: everthis

902-numbers-at-most-n-given-digit-set.js

@@ -1,3 +1,38 @@
+/**
+ * @param {string[]} digits
+ * @param {number} n
+ * @return {number}
+ */
+const atMostNGivenDigitSet = function(digits, n) {
+  let res = 0
+  const str = `${n}`, len = str.length
+  const { pow } = Math, base = digits.length
+  for(let i = 1; i < len; i++) {
+    res += pow(base, i)
+  }
+  
+  dfs(0)
+  
+  return res
+  
+  function dfs(pos) {
+    if(pos === len) {
+      res++
+      return
+    }
+    for(const ch of digits) {
+      if(str[pos] > ch) {
+        res += pow(base, len - 1 - pos)
+      } else if(str[pos] === ch) {
+        dfs(pos + 1)
+      }
+    }
+  }
+};
+
+// another
+
+
 /**
  * @param {string[]} digits
  * @param {number} n