I - 9 POJ - 1426 Find The Multiple

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

问题链接：https://vjudge.net/contest/279607#problem/I

问题分析：
找出一个由1和0组成的数字能把给出的n整除。 用简单bfs+队列

#include
#include
using namespace std;
void bfs(int n)
{
	queueq;
	q.push(1);
	while (!q.empty())
	{
		unsigned long long sum = q.front();
		q.pop();
		if (sum%n == 0)
		{
			cout << sum << endl;
			return;
		}
		else
		{
			q.push(sum * 10);
			q.push(sum * 10 + 1);
		}
	}
}
int main()
{
	int n;
	while (cin >> n)
	{
		if (n == 0)break;
		bfs(n);
	}
	return 0;
}