算法：深搜（水题）；

Given a positive integer n, write a program to find out a nonzero multiple m of n whose decimal representation contains only the digits 0 and 1. You may assume that n is not greater than 200 and there is a corresponding m containing no more than 100 decimal
digits.

Input

The input file may contain multiple test cases. Each line contains a value of n (1 <= n <= 200). A line containing a zero terminates the input.

Output

For each value of n in the input print a line containing the corresponding value of m. The decimal representation of m must not contain more than 100 digits. If there are multiple solutions for a given value of n, any one of them is acceptable.

Sample Input

2

6

19

0

Sample Output

10

100100100100100100

111111111111111111

代码：

#include <iostream>

#include <cstring>

#include <iomanip>

#include <stdio.h>

using namespace std;

int p;

void dfs(unsigned __int64 t,int n,int k)

{

	if(p) return;

	if(t%n==0)

	{

		cout<<t<<endl;

		p=1;

		return;

	}

	if(k==19) return;

	dfs(t*10+1,n,k+1);

	dfs(t*10,n,k+1);

}

int main()

{

	int n,m,k;

	while(cin>>n&&n)

	{

		p=0;

		k=1;

		dfs(1,n,k);

	}

}