HDU 4474 Yet Another Multiple Problem(搜索剪枝)

#include<cstring>
#include<cstdio>
#include<iostream>
#include<algorithm>
#include<queue>

using namespace std;

int num[15],vis[15],len,vis1[100005];
int a,n;
string ans;

struct node
{
string s;
int m;
node(){}
node(string _s,int _m){s=_s,m=_m;}
};

queue<node>que;

void bfs()
{
while(que.size()) que.pop();
string s;
for(int i=0;i<len;i++)
{
if(num[i]==0) continue;
s="";
char c=num[i]+'0';
s+=c;
if(num[i]%a==0)
{
ans=s;
return ;
}
que.push(node(s,num[i]%a));
}
while(que.size())
{
node k=que.front();
que.pop();
if(k.s.length()>ans.length()&&ans!="") return ;
if(k.m==0)
{
if(ans=="") ans=k.s;
else ans=min(ans,k.s);
continue;
}
if(vis1[k.m]) continue;
vis1[k.m]=1;
for(int i=0;i<len;i++)
{
char c=num[i]+'0';
node tmp=k;
tmp.s+=c;
tmp.m=tmp.m*10+num[i];
tmp.m%=a;
que.push(tmp);
}
}
}

int main()
{
int ca=1;
while(scanf("%d",&a)!=EOF)
{
memset(vis,0,sizeof vis);
memset(vis1,0,sizeof vis1);
scanf("%d",&n);
for(int i=0;i<n;i++)
{
int temp;
scanf("%d",&temp);
vis[temp]=1;
}
len=0;
for(int i=0;i<10;i++)
{
if(!vis[i]) num[len++]=i;
}
ans="";
bfs();
printf("Case %d: ",ca++);
if(ans=="") cout<<"-1"<<endl;
else cout<<ans<<endl;
}
return 0;
}