ZOJ 1530 - Find The Multiple

Posted 2020-06-08

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。

  

 1 #include <iostream>
 2 #include <queue>
 3 #include <cstdio>
 4 using namespace std;
 5 queue<unsigned long long> s;  
 6 int n;//输入 
 7 unsigned long long temp,p;
 8 void bfs()
 9 {
10     while(!s.empty())
11     s.pop();
12     temp=1;
13     s.push(temp);
14     while(!s.empty())
15     {
16         p=s.front();
17         s.pop();
18         if(p%n==0)
19         {
20             printf("%lld\n",p);//lld！ 
21             break;
22         }
23         s.push(p*10);
24         s.push(p*10+1);  
25     } 
26 }
27 int main(){
28     while(scanf("%d",&n),n)
29     {
30         bfs();
31     }
32     return 0;
33 }