poj1426 - Find The Multiple [bfs 记录路径]

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转：http://blog.csdn.net/wangjian8006/article/details/7460523

(比较好的记录路径方案)

 #include<iostream>
 #include<cstring>
 #include<cstdlib>
 #include<cstdio>
 #include<algorithm>
 #include<cmath>
 #include<queue>
 #include<map>
 #include<set>
 #include<stack>
 #include<string>

 #define N 1000005
 #define M 9
 #define mod 1000000007
 //#define p 10000007
 #define mod2 1000000000
 #define ll long long
 #define LL long long
 #define eps 1e-6
 #define inf 1000000
 #define maxi(a,b) (a)>(b)? (a) : (b)
 #define mini(a,b) (a)<(b)? (a) : (b)

 using namespace std;

 int n;
 typedef struct
 {
     int v;
     int yu;
     int num;
     int pre;
 }PP;

 int tot;
 int vis[];
 PP ans[N];

 void ini()
 {
     tot=;
     memset(vis,,sizeof(vis));
 }

 void out(int now)
 {
    // for(int i=0;i<=1;i++)
     //printf(" v=%d pre=%d\n",ans[i].v,ans[i].pre);
     //printf(" now=%d v=%d pre=%d\n",now,ans[now].v,ans[now].pre);
     if(ans[now].pre!=-){

         out(ans[now].pre);

     }
     printf("%d",ans[now].v);
 }

 void bfs()
 {
     queue<PP>q;
     PP te,nt;
     te.v=;
     te.pre=-;
     te.num=;
     te.yu=%n;
     ans[].v=;
     ans[].pre=-;
     tot=;
     vis[]=;
     q.push(te);

     while(q.size()>=)
     {

         te=q.front();
         q.pop();
        // printf(" v=%d yu=%d num=%d pre=%d\n",te.v,te.yu,te.num,ans[te.num].pre);
         if(te.yu==){
             //printf(" num=%d\n",te.num);
             out(te.num);
             printf("\n");
             return;
         }
         nt.pre=te.num;
         nt.yu=(te.yu*)%n;
         if(vis[nt.yu]==){
             vis[nt.yu]=;
             nt.num=tot;
             ans[tot].v=;
             ans[tot].pre=te.num;
             tot++;

             nt.v=;
             q.push(nt);
         }
         nt.yu=(te.yu*+)%n;
         if(vis[nt.yu]==){
             vis[nt.yu]=;
             nt.num=tot;
             ans[tot].v=;
             ans[tot].pre=te.num;
             tot++;
             nt.v=;
             q.push(nt);
         }
     }
 }

 void solve()
 {
     bfs();
 }

 int main()
 {
     //freopen("data.in","r",stdin);
    // freopen("data.out","w",stdout);
     //scanf("%d",&T);
     //for(int ccnt=1;ccnt<=T;ccnt++)
     //while(T--)
     while(scanf("%d",&n)!=EOF)
     {
         if(n==) break;
         ini();
         solve();
 //        out();
     }

     return ;
 }