ZOJ 1136 Multiple(BFS)

#include <iostream>
#include <cstdio>
#include <memory.h>
#include <queue>
#include <cstring>
#include <string>
#include <algorithm>
using namespace std;
const int maxn=5100;

int n,m,a[12];
bool vis[maxn];
struct node
{
	string num;
	int mod;
	node(string str="",int mmod=0):num(str),mod(mmod){}
};
string bfs(){
	memset(vis,0,sizeof(vis));
	queue<node>q;
	q.push(node("",0));
	while (q.size()){
		node t=q.front();
		q.pop();
		if(t.num!=""&&t.mod==0){
			return t.num;
		}
		for (int i=0;i<=10;++i){
			if(!a[i])continue;
			node temp=t;
			temp.num=temp.num+(char)('0'+i);
			temp.mod=(temp.mod*10+i)%n;
			if(!vis[temp.mod]&&temp.num!="0"){
				vis[temp.mod]=1;
				q.push(temp);
			}
		}
	}
	return "";
}
int main(){
	while (scanf("%d%d",&n,&m)==2){
		memset(a,0,sizeof(a));
		for (int i=0;i<m;++i){
			int t;
			scanf("%d",&t);
			a[t]=1;
		}
		string ans="0";
		if(n!=0)
			ans=bfs();
		if(ans!=""){
			printf("%s\n",ans.c_str());
		}else{
			printf("0\n");
		}
	}
	return 0;
}