Remember the Word UVALive - 3942——（trie+DP）

總結

這個關鍵點在於，每個單詞的最大長度是1e2，然後我們可以倒序枚舉後綴，dp枚舉向右遞推最多100，O(L*100+Slog100)

題目鏈接

//#pragma GCC optimize(2)
#include<bits/stdc++.h>
//typedef long long ll;
#define ull       unsigned long long
#define int       long long
#define F           first
#define S           second
#define endl        "\n"//<<flush
#define eps         1e-6
#define base        131
#define lowbit(x)   (x&(-x))
#define PI          acos(-1.0)
#define inf         0x3f3f3f3f
#define MAXN        0x7fffffff
#define INF         0x3f3f3f3f3f3f3f3f
#define ferma(a,b)  pow(a,b-2)
#define pb          push_back
#define all(x)      x.begin(),x.end()
#define memset(a,b) memset(a,b,sizeof(a));
#define IOS         ios::sync_with_stdio(false),cin.tie(0),cout.tie(0);
using namespace std;
void file()
{
#ifdef ONLINE_JUDGE
#else
    freopen("D:/LSNU/codeforces/duipai/data.txt","r",stdin);
    //  freopen("D:/LSNU/codeforces/duipai/WA.txt","w",stdout);
#endif
}
const int N=3e5+5;
const int M=4e6+5;
const int mod=20071027;
int son[M][26],pos=0,cnt[M],dp[N];
void insert(string &t)
{
    int p=0;
    for(auto it:t)
    {
        int &value=son[p][it-'a'];
        if(!value)
            value=++pos;
        p=value;
    }
    cnt[p]++;
}
void query(int ac,string &s,int len)
{
    int p=0;
    for(int i=ac;i<len;i++)
    {
        int value=son[p][s[i]-'a'];
        if(!value)
            break;
        if(cnt[value])
            dp[ac]=(dp[ac]+cnt[value]*dp[i+1]%mod)%mod;
        p=value;
    }
}
signed main()
{
    IOS;
    // file();
    string s,t;
    int num=0;
    while(cin>>s)
    {
        int n;
        cin>>n;
        while(n--)
        {
            cin>>t;
            insert(t);
        }
        int len=s.size();
        dp[len]=1;
        for(int i=len-1;i>=0;i--)
        {
            query(i,s,len);
        }
        cout<<"Case "<<++num<<": ";
        cout<<dp[0]<<endl;
        for(int i=0;i<=len;i++)
            dp[i]=0;
        for(int i=0;i<=pos;i++)
        {
            memset(son[i],0);
            cnt[i]=0;
        }
        pos=0;
    }
    return 0;
}