(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=4001*101;
const int maxm=3e5+10;
const int mod=20071027;
struct Trie
{
    int ch[maxn][26];
    int val[maxn];
    int sz;
    Trie()
    {
        sz=1;
        memset(ch[0],0,sizeof(ch[0]));
    }
    int idx(char c)
    {
        return c-'a';
    }

    void insert(char *s,int v)
    {
        int i,u=0,n=strlen(s);
        for(i=0; i<n; i++)
        {
            int c=idx(s[i]);
            if(!ch[u][c])
            {
                memset(ch[sz],0,sizeof(ch[sz]));
                val[sz]=0;
                ch[u][c]=sz++;
            }
            u=ch[u][c];
        }
        val[u]=v;
    }
} e;
char str[maxm];
char a[101];
LL dp[maxm];
int main()
{
    int tt=0;
    while(scanf("%s",str)!=EOF)
    {
        int i,j,k,n,m,u;
        scanf("%d",&n);
        memset(e.ch[0],0,sizeof(e.ch[0]));
        e.sz=1;
        for(i=0; i<n; i++)
        {
            scanf("%s",a);
            e.insert(a,1);
        }
        m=strlen(str);
        memset(dp,0,sizeof(dp));
        dp[m]=1;
        for(i=m-1; i>=0; i--)
        {
            u=0;
            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+1];
            }
            dp[i]%=mod;
        }
        printf("Case %d: %lld
",++tt,dp[0]);
    }
    return 0;
}