Create smallest-number-with-given-digit-product.cpp

Author: kamyu104

C++/smallest-number-with-given-digit-product.cpp

@@ -0,0 +1,20 @@
+// Time:  O(logn)
+// Space: O(logn)
+
+// greedy
+class Solution {
+public:
+    string smallestNumber(long long n) {
+        string result;
+        for (int d = 9; d >= 2; --d) {
+            for (; n % d == 0; n /= d) {
+                result.push_back('0' + d);
+            }
+        }
+        reverse(begin(result), end(result));
+        if (empty(result)) {
+            result = "1";
+        }
+        return n == 1 ? result : "-1";
+    }
+};