POJ 1426 Find The Multiple（bfs）

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 <cstdio>
#include <queue>
#include <algorithm>
using namespace std;

void bfs(int n)
{
  queue<long long> q;
  q.push(1);
  while (!q.empty()){
    long long t=q.front();
    q.pop();
    if (t%n==0){
      cout<<t<<endl;
      return;
    }
    q.push(t*10);
    q.push(t*10+1);
  }
}
int main()
{
  int n;
  while (scanf("%d", &n)!=EOF && n){
    bfs(n);
  }
  return 0;
}