(bfs)E - Find The Multiple POJ - 1426

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

#include<iostream>
#include<stdio.h>
#include<string.h>
#include<queue>
using namespace std;
typedef long long ll;
ll n;
void bfs()
{
	queue<ll> q;
	q.push(1);
	while(!q.empty())
	{
		ll x=q.front();
		q.pop();
		if(x%n==0)
		{
			printf("%lld\n",x);
			return;
		}
		else
		{
			q.push(x*10);
			q.push(x*10+1);
		}
	}
}
int main()
{
	while(scanf("%lld",&n)&&n)
	{
		bfs();
	}
}