Find The Multiple poj-1426

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 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

dfsAC

#include<iostream>
#include<queue>
using namespace std;
typedef long long ll;
int n;
int flag;
ll val;
void dfs(ll s,int k){
	if(k==19) return;
	if(flag) return;//防止又进行深搜
	if(s%n==0){
		flag=1;
		cout<<s<<endl;
		return;
	}
	dfs(s*10,k+1);
	dfs(s*10+1,k+1); 
}
int main(){
	while(~scanf("%d",&n)){
		if(n==0) break;
		flag=0;
	    dfs(1,0);
	}
	return 0;
}

bfs超时（待优化）

#include<iostream>
#include<queue>
using namespace std;
typedef long long ll;
ll n;
ll bfs(ll s){
	queue<ll> q;
	while(!q.empty()) q.pop();
	q.push(s);
	while(!q.empty()){
		ll val=q.front();
		if(val%n==0)
		  return val;
		q.pop();
		q.push(val*10);
		q.push(val*10+1);
	}	
}
int main(){
	while(~scanf("%lld",&n)){
		if(n==0) break;
		cout<<bfs(1)<<endl;
	}
	return 0;
}