(Trie) uvalive 3942 Remember the word

题意：告诉你一个母串和子串，能用多少种不同的方案组合出母串。

思路：字典树（显然）+DP

DP： dp[i]+=dp[j+1]  i<=j<=m-1,且i到j的字符串能在字典树中找到。也就等价dp[i]=1*dp[j+1]

 #include <cstdio>
 #include <cstring>
 #include <cmath>
 #include <cstdlib>
 #include <iostream>
 #include <algorithm>
 #include <queue>
 #include <map>
 #include <vector>
 using namespace std;

 #define LL long long
 const int maxn=*;
 const int maxm=3e5+;
 const int mod=;
 struct Trie
 {
     int ch[maxn][];
     int val[maxn];
     int sz;
     Trie()
     {
         sz=;
         memset(ch[],,sizeof(ch[]));
     }
     int idx(char c)
     {
         return c-'a';
     }

     void insert(char *s,int v)
     {
         int i,u=,n=strlen(s);
         for(i=; i<n; i++)
         {
             int c=idx(s[i]);
             if(!ch[u][c])
             {
                 memset(ch[sz],,sizeof(ch[sz]));
                 val[sz]=;
                 ch[u][c]=sz++;
             }
             u=ch[u][c];
         }
         val[u]=v;
     }
 } e;
 char str[maxm];
 char a[];
 LL dp[maxm];
 int main()
 {
     int tt=;
     while(scanf("%s",str)!=EOF)
     {
         int i,j,k,n,m,u;
         scanf("%d",&n);
         memset(e.ch[],,sizeof(e.ch[]));
         e.sz=;
         for(i=; i<n; i++)
         {
             scanf("%s",a);
             e.insert(a,);
         }
         m=strlen(str);
         memset(dp,,sizeof(dp));
         dp[m]=;
         for(i=m-; i>=; i--)
         {
             u=;
             for(j=i; j<m; j++)
             {
                 int c=e.idx(str[j]);
                 if(!e.ch[u][c])
                     break;
                 u=e.ch[u][c];
                 if(e.val[u])
                     dp[i]+=dp[j+];
             }
             dp[i]%=mod;
         }
         printf("Case %d: %lld\n",++tt,dp[]);
     }
     return ;
 }