学步园

AC自动机+状态压缩递推

#include <iostream>
#include <cstdio>
#include <cstdlib>
#include <cmath>
#include <queue>
#include <algorithm>
#include <vector>
#include <cstring>
#include <stack>
#include <cctype>
#include <utility>   
#include <map>
#include <string>  
#include <climits> 
#include <set>
#include <string>    
#include <sstream>
#include <utility>   
#include <ctime>

using std::priority_queue;
using std::vector;
using std::swap;
using std::stack;
using std::sort;
using std::max;
using std::min;
using std::pair;
using std::map;
using std::string;
using std::cin;
using std::cout;
using std::set;
using std::queue;
using std::string;
using std::istringstream;
using std::make_pair;
using std::getline;
using std::greater;
using std::endl;
using std::multimap;

typedef long long LL;
typedef unsigned long long ULL;
typedef pair<int, int> PAIR;
typedef multimap<int, int> MMAP;

const int MAXN(110);
const int SIGMA_SIZE(26);
const int MAXM(110);
const int MAXE(4000010);
const int MAXH(18);
const int INFI((INT_MAX-1) >> 2);
const int BASE(131);
const int MOD(20090717);
const ULL LIM(1000000000000000ull);

struct AC
{
	int ch[MAXN][SIGMA_SIZE];
	int val[MAXN];
	int f[MAXN];
	int size;
	
	void init()
	{
		memset(ch[0], 0, sizeof(ch[0]));
		f[0] = val[0] = 0;
		size = 1;
	}
	
	inline int idx(char temp)
	{
		return temp-'a';
	}
	
	void insert(char *S, int tv)
	{
		int u = 0, id;
		for(; *S; ++S)
		{
			id = idx(*S);
			if(!ch[u][id])
			{
				memset(ch[size], 0, sizeof(ch[size]));
				val[size] = 0;
				ch[u][id] = size++;
			}
			u = ch[u][id];
		}
		val[u] |= (1 << tv);
	}
	
	int que[MAXN];
	int front, back;
	void construct()
	{
		front = back = 0;
		int cur, u;
		for(int i = 0; i < SIGMA_SIZE; ++i)
		{
			u = ch[0][i];
			if(u)
			{
				que[back++] = u;
				f[u] = 0;
			}
		}
		while(front < back)
		{
			cur = que[front++];
			for(int i = 0; i < SIGMA_SIZE; ++i)
			{
				u = ch[cur][i];
				if(u)
				{
					que[back++] = u;
					f[u] = ch[f[cur]][i];
					val[u] |= val[f[u]];
				}
				else
					ch[cur][i] = ch[f[cur]][i];
			}
		}
	}
};

AC ac;
int table[26][110][1 << 10];

void solve(int len, int m, int K)
{
	int lim = (1 << m);
	memset(table, 0, sizeof(table));
	table[0][0][0] = 1;
	for(int i = 0; i < len; ++i)
		for(int j = 0; j < ac.size; ++j)
			for(int k = 0; k < lim; ++k)
				if(table[i][j][k])
				{
					int tv = table[i][j][k];
					for(int k2 = 0; k2 < SIGMA_SIZE; ++k2)
					{
						int ts = ac.ch[j][k2];
						int &temp = table[i+1][ts][k|ac.val[ts]];
						temp += tv;
						if(temp >= MOD)
							temp -= MOD;
					}
				}
	int ans = 0;
	for(int j = 0; j < lim; ++j)
	{
		int cnt = 0, tj = j;
		while(tj)
		{
			++cnt;
			tj ^= tj&(-tj);
		}
		if(cnt < K)
			continue;
		for(int i = 0; i < ac.size; ++i)
		{
			ans += table[len][i][j];
			if(ans >= MOD)
				ans -= MOD;
		}
	}
	printf("%d\n", ans);
}

char str[15];

int main()
{
	int len, m, k;
	while(scanf("%d%d%d", &len, &m, &k), len+m+k)
	{
		ac.init();
		for(int i = 0; i < m; ++i)
		{
			scanf("%s", str);
			ac.insert(str, i);
		}
		ac.construct();
		solve(len, m, k);
	}
	return 0;
}