UVA1401 （字典树加简单dp）

#pragma GCC optimize(2)
#include <bits/stdc++.h>
#define ll long long
using namespace std;
const int N = 5e5+;
const int mod=;
const int sigma_size=;
int dp[N];
char str[N];
char s[];
struct Trie{
    int ch[N][sigma_size];
    int val[N];
    int sz;
    Trie(){sz=;memset(ch[],,sizeof(ch[]));}
    int idx(char c) {return c-'a';}
    void reset(){memset(ch,,sizeof(ch));memset(val,,sizeof(val));sz=;}
    void insert(char *s,int v)
    {
        int u=,n=strlen(s);
        for(int 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;
    }
    int query(char *s,int a)
    {
        int u=,res=;
        for(int i=a;s[i];++i)
        {
            int c=idx(s[i]);
            if(!ch[u][c])
                return res;
            u=ch[u][c];
            if(val[u])
            {
                res+=dp[i+];
                res%=mod;
            }
        }
        return res;
    }
};
Trie T;
int main()
{
    int kase=;
    while(scanf("%s",str)!=EOF)
    {
        int n,m=strlen(str);
        scanf("%d",&n);
        T.reset();
        memset(dp,,sizeof(dp));
        for(int i=;i<=n;i++)
        {
            scanf("%s",s);
            T.insert(s,);
        }
        dp[m]=;
        for(int i=m-;i>=;i--)
        {
            dp[i]=T.query(str,i);
        }
        printf("Case %d: %d\n",++kase,dp[]);
    }
    return ;
}