Given a positive integer a, find the smallest positive integer b whose multiplication of each digit equals to a.
If there is no answer or the answer is not fit in 32-bit signed integer, then return 0.
Example 1
Input:
48
Output:
68
Example 2
Input:
15
Output:
35
class Solution { public: int smallestFactorization(int a) { if (a < 2) return a; string s; for (int i = 9; i >= 2; i--) { while (a % i == 0) { s.insert(s.begin(), (‘0‘ + i)); a /= i; } } return (a > 1 || s.size() > 10 || stol(s) > INT_MAX) ? 0 : stoi(s); } };
原文：http://www.cnblogs.com/jxr041100/p/7889010.html