Find The Multiple POJ - 1426

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

题解：

#include <iostream>
#include<cstdio>
#include<cstdlib>
#include<algorithm>
#include <cstring>
#include <queue>
#include <cmath>
#include <string>
#define INF 0x7f7f7f7f
typedef long long ll;

using namespace std;
int n;
int flag;
void dfs(ll ans, int k)
{
	if (flag == 1||k==19)
	{
		return ;
	}
	if (ans%n==0)
	{
		printf("%lld\n", ans);
		flag = 1;
		return ;
	}
	else
	{
		dfs(ans*10,k+1);
		dfs(ans*10+1,k+1);
	}
	return ;
}
int main()
{
	while (scanf("%d", &n) && n!=0)
	{
		flag = 0;
		dfs(1,0);
	}
	return 0;
}