HDU 5129 Yong Zheng's Death

  1 #include<cstring>
  2 #include<cstdio>
  3 #include<queue>
  4 using namespace std;
  5 
  6 typedef long long LL;
  7 const LL MAXN=300010;
  8 const LL SIGMA_SIZE=26;
  9 struct Trie
 10 {
 11     LL ch[MAXN][SIGMA_SIZE];
 12     LL fa[MAXN];
 13     LL sz;                                              //节点总数
 14     Trie() { sz=1; fa[0]=-1; memset(ch[0],0,sizeof(ch[0])); }
 15     LL idx(char c) { return c-‘a‘; }                     //节点c的编号
 16     void clear() { sz=1; fa[0]=-1; memset(ch[0],0,sizeof(ch[0])); }
 17 
 18     //在Trie中插入字符串s
 19     void insert(char *s)
 20     {
 21         LL u=0,n=strlen(s);
 22         for(LL i=0;i<n;i++)
 23         {
 24             LL c=idx(s[i]);
 25             if(!ch[u][c])                                //节点不存在
 26             {
 27                 memset(ch[sz],0,sizeof(ch[sz]));
 28                 fa[sz]=u;
 29                 ch[u][c]=sz++;                            //新建节点
 30             }
 31             u=ch[u][c];                                    //往下走
 32         }
 33     }
 34 
 35     //AC自动机部分
 36     LL f[MAXN];
 37     LL deg[MAXN];                            
 38     LL sum[MAXN];                             //sum[i]表示以Si为后缀的前缀的数量
 39     void getFail()
 40     {
 41         queue<LL> q;
 42         f[0]=0;
 43         //初始化队列
 44         for(LL c=0;c<SIGMA_SIZE;c++)
 45         {
 46             LL u=ch[0][c];
 47             if(u) { f[u]=0; q.push(u); }
 48         }
 49         //按BFS顺序计算失配函数
 50         while(!q.empty())
 51         {
 52             LL r=q.front(); q.pop();
 53             for(LL c=0;c<SIGMA_SIZE;c++)
 54             {
 55                 LL u=ch[r][c];
 56                 if(!u) { ch[r][c]=ch[f[r]][c]; continue; }
 57                 q.push(u);
 58                 LL v=f[r];
 59                 f[u]=ch[v][c];
 60             }
 61         }
 62         for(LL i=1;i<sz;i++) { deg[i]=0; sum[i]=1; }
 63         for(LL i=1;i<sz;i++) deg[f[i]]++;
 64         queue<LL> Q;
 65         for(LL i=1;i<sz;i++) if(!deg[i]) Q.push(i);
 66         while(!Q.empty())
 67         {
 68             LL u=Q.front(); Q.pop();
 69             sum[f[u]]+=sum[u];
 70             deg[f[u]]--;
 71             if(!deg[f[u]]) Q.push(f[u]);
 72         }
 73     }
 74 
 75     void solve()
 76     {
 77         LL tot=0;
 78         for(LL i=1;i<sz;i++) if(f[i])
 79         {
 80             LL j=f[i];
 81             LL p=i;
 82             while(j)
 83             {
 84                 p=fa[p];
 85                 j=fa[j];
 86             }
 87             tot+=sum[p]-1;
 88         }
 89         printf("%lld\n",1LL*(sz-1)*(sz-1)-tot);
 90     }
 91 };
 92 Trie T;
 93 int main()
 94 {
 95 #ifdef LOCAL
 96     freopen("in.txt","r",stdin);
 97 #endif
 98     LL n;
 99     while(scanf("%lld",&n) && n)
100     {
101         scanf("%lld",&n);
102         for(LL i=1;i<=n;i++)
103         {
104             char s[50];
105             scanf("%s",s);
106             T.insert(s);
107         }
108         T.getFail();
109         T.solve();
110         T.clear();
111     }
112     return 0;
113 }