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

思路：DFS  刚开始没认真看题，后面发现只需要输出符合要求的就行

AC代码：

#include<iostream>
#include<cstdio>
using namespace std;
long long int n;
int flag=0;

void dfs(unsigned long long int a,int k){
    if(flag)return ;
   if(a%n==0){
   cout<<a<<endl;
     flag=1;
    return ;
    }
   if(k>=20)return ;
  dfs(a*10,k+1);
  dfs(a*10+1,k+1);
}

int main(){
 while(cin>>n&&n){
   flag=0;
   dfs(1,1);
 }
return 0;
}