【搜索】POJ1426：Find The Multiple

Description

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

题意：输入一个数，要求输出一个数满足是这个数的倍数，而且只由1和0构成。

分析：BFS用c++交超时，g++过了

 

#include <iostream>
#include <cstdio>
#include <cstring>
#include <queue>
using namespace std;
int n;
queue<long long> q;
long long bfs()
{
    while(!q.empty())
    {
        q.pop();
    }
    q.push(1);
    while(!q.empty())
    {
        long long now=q.front();
        q.pop();
        if(now%n==0)
            return now;
        q.push(now*10);
        q.push(now*10+1);
    }
}
int main()
{
    while(~scanf("%d",&n)&&n)
    {
        long long ans=bfs();
        printf("%lld
",ans);
    }
    return 0;
}