[模拟]uva993 Product of digits

  Product of digits 

For a given non-negative integer number N , find the minimal natural Q such that the product of all digits of Q is equal N .

Input 

The first line of input contains one positive integer number, which is the number of data sets. Each subsequent line contains one data set which consists of one non-negative integer number N (0N10⁹) .

Output 

For each data set, write one line containing the corresponding natural number Q or `-1' if Q does not exist.

Sample Input 

3 1 10 123456789

Sample Output 

1 25 -1

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题意：给你一个大于等于0 的整数N，请你你找到最小的自然数Q ，使得在Q 中所有数字（digit）的乘积等于N 。

思路：比较简单了，就是判断这个数能否被分解成一串1-9的数字相乘得到。

#include<iostream>#include<string>using namespace std;int main(){    int num;    cin>>num;    while(num--)    {        int n;        cin>>n;        if(n==0||n==1)        {            cout<<n<<endl;            continue;        }        string str="";        for(int i=9;i>=2;i--)        {            while(n%i==0)            {                char ch=('0'+i);                str=str+ch;                n=n/i;            }        }        if(n!=1) cout<<"-1"<<endl;        else        {            for(int i=str.size()-1;i>=0;i--)                cout<<str[i];            cout<<endl;        }    }    return 0;}