No matter what language you use on the OJ, you may refer to Stefan‘s post for a solution. The C++ is rewritten below, just really concise.
1 class Solution { 2 public: 3 bool isUgly(int num) { 4 for (int i = 2; i < 6 && num; i++) 5 while (!(num % i)) num /= i; 6 return num == 1; 7 } 8 };
Note that i = 4 will simply be skipped after we try to divide by 2 as much as possible.
原文：http://www.cnblogs.com/jcliBlogger/p/4742618.html