ZOJ 1530 - 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 (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=;
     s.push(temp);
     while(!s.empty())
     {
         p=s.front();
         s.pop();
         if(p%n==)
         {
             printf("%lld\n",p);//lld！
             break;
         }
         s.push(p*);
         s.push(p*+);
     }
 }
 int main(){
     while(scanf("%d",&n),n)
     {
         bfs();
     }
     return ;
 }