650. 2 Keys Keyboard

甚至不用dp写，直接用递归操作就可以

class Solution {public:    int minSteps(int n) {        if(n==1)            return 0;        // find min divided        for(int i=2;i<=n/2;i++)        {            if(n%i==0)                return minSteps(n/i)+i;        }        return n;    }};