ZOJ 1530

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 (0) 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

大致题意：

  给个n,找n的十进制倍数，仅有 0 和 1 组成，找一个就行，随便哪一个。

解题思路：

  观察以下0，1串： 

  1 

  10 11

  100 101 110 111

  从n=1开始， 重复 n*10 与 n*10+1 ，由此遍历所有01串。

  BFS，DFS皆可，以下采用DFS。

  

#include <iostream>
#include <queue>
#include <cstdio>
using namespace std;
queue<unsigned long long> s;  
int n;//输入 
unsigned long long temp,p;
void bfs()
{
    while(!s.empty())
    s.pop();
    temp=1;
    s.push(temp);
    while(!s.empty())
    {
        p=s.front();
        s.pop();
        if(p%n==0)
        {
            printf("%lld
",p);//lld！ 
            break;
        }
        s.push(p*10);
        s.push(p*10+1);  
    } 
}
int main(){
    while(scanf("%d",&n),n)
    {
        bfs();
    }
    return 0;
}