LA-3942 （字典树模板）

  分析：字典树+DP，当做字典树模板来做了。

#include <cstdio>
#include <iostream>
#include <algorithm>
#include <cstring>
#include <cmath>
using namespace std;
string m,s[4001];
const int maxnode=400000,tot_size=26;
int num,n,f[300001];
struct Trie
{
    int ch[maxnode][tot_size];
    int val[maxnode];
    int tot;
    void build()
    {
        tot=1;
        memset(ch[0],0,sizeof(ch[0]));
    }
    int idx(char c) { return c - 'a'; }
    void insert(string s,int v)
    {
        int u=0,n=s.length();
        for(int i=0;i < n;i++)
        {
            int c=idx(s[i]);
            if(!ch[u][c])
            {
                memset(ch[tot],0,sizeof(ch[tot]));
                val[tot]=0;
                ch[u][c]=tot++;
            }
            u=ch[u][c];
        }
        val[u]=v;
    }
    int find(string s,int now)
    {
        int u=0,n=s.length(),ans=0;
        for(int i=0;i < n;i++)
        {
            int c=idx(s[i]);
            if(!ch[u][c]) return ans;
            u=ch[u][c];
            if(val[u]) ans=(ans+f[now+val[u]])%20071027;
        }
        return ans;
    }
} tree;
int main()
{
    cin.sync_with_stdio(false);
    while(cin>>m)
    {
        cin>>n;
        tree.build();
        int Max=0;
        for(int i=1;i <= n;i++)
        {
            cin>>s[i];
            tree.insert(s[i],int(s[i].length()));
            Max=max(Max,int(s[i].length()));
        }
        memset(f,0,sizeof(f));
        int l=m.length();
        f[l]=1;
        for(int i=l-1;i >= 0;i--)
         f[i]=(f[i]+tree.find(m.substr(i,min(Max,l-i)),i))%20071027;
        cout<<"Case "<<++num<<": "<<f[0]<<endl;
    }
}