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:给你一个数n,找出一个他的倍数m。(我被样例唬住了)
题解:用bfs,从1开始,两个方向(因为只有0和1组成) x*10 x*10+1,进队即可,然后判断是否是n的倍数,是就输出。
#include<iostream> #include<queue> typedef long long ll; using namespace std; int n; void bfs(int n){ queue<ll>q; q.push(1); ll head; while(!q.empty()){ head = q.front(); q.pop(); if(!(head%n)) { cout<<head<<endl;break; } q.push(head*10); q.push(head*10+1); } } int main(){ while(cin>>n && n){ bfs(n); } return 0; }