学步园

Trie图（AC自动机）+dp，另外，这题卡常数~

#include <cstdio>
  2 #include <cstring>
  3 
  4 usingnamespace std;
  5 
  6 constint NS =26;
  7 constint MAXL =16;
  8 constint MAXN =128;
  9 constint MOD =20090717;
 10 
 11 constint bits[] = {0,1,1,2,1,2,2,3,1,2,2,3,2,3,3,4,1,2,2,3,2,3,3,4,2,3,3,4,3,4,4,5};
 12 
 13 int N;
 14 int M;
 15 int K;
 16 
 17 int node;
 18 int tag[MAXN];
 19 int suffix[MAXN];
 20 int next[MAXN][NS];
 21 
 22 int queue[MAXN];
 23 
 24 int dp[NS][MAXN][1<<10];
 25 
 26 int bitCount(int k)
 27 {
 28 return bits[k &31] + bits[(k >>5) &31];
 29 }
 30 
 31 int TrieInit()
 32 {
 33     node =0;
 34     memset(tag,0,sizeof(tag));
 35     memset(suffix,-1,sizeof(suffix));
 36     memset(next,-1,sizeof(next));
 37 return node++;
 38 }
 39 
 40 void TrieInsert(char* word,int id,int root)
 41 {
 42 char* key;
 43 int tmp;
 44 
 45     key = word;
 46     tmp = root;
 47 
 48 while (*key)
 49     {
 50 int idx = (*key++) -'a';
 51 if (next[tmp][idx] ==-1)
 52             next[tmp][idx] = node++;
 53         tmp = next[tmp][idx];
 54     }
 55     tag[tmp] = (1<< id);
 56 }
 57 
 58 void getSuffix(int root)
 59 {
 60 int qh =-1;
 61 int qe =0;
 62 
 63     queue[0] = root;
 64 
 65 while (qh != qe)
 66     {
 67         qh++;
 68 
 69 int tmp = queue[qh];
 70 for (int i =0;i < NS;i++)
 71 if (next[tmp][i] !=-1)
 72             {
 73 int now = next[tmp][i];
 74 int p = suffix[tmp];
 75 while (p !=-1&& next[p][i] ==-1) p = suffix[p];
 76 if (p ==-1) suffix[now] = root;
 77 else
 78                 {
 79                     suffix[now] = next[p][i];
 80                     tag[now] |= tag[next[p][i]];
 81                 }
 82                 queue[++qe] = now;
 83             }
 84 else
 85             {
 86 int p = suffix[tmp];
 87 while (p !=-1&& next[p][i] ==-1) p = suffix[p];
 88 if (p ==-1) next[tmp][i] = root;
 89 else next[tmp][i] = next[p][i];
 90             }
 91     }
 92 }
 93 
 94 int main()
 95 {
 96 char word[MAXL];
 97 while (scanf("%d %d %d",&N,&M,&K) != EOF)
 98     {
 99 if (N ==0&& M ==0&& K ==0)
100 break;
101 
102 int root = TrieInit();
103 for (int i =0;i < M;i++)
104         {
105             scanf("%s",word);
106             TrieInsert(word,i,root);
107         }
108         getSuffix(root);
109 
110         memset(dp,0,sizeof(dp));
111 
112         dp[0][0][0] =1;
113 
114 for (int i =1;i <= N;i++)
115 for (int j =0;j < node;j++)
116 for (int k =0;k <1<< M;k++)
117                 {
118 if(dp[i-1][j][k] ==0) continue; // without this TLE
119 for (int l =0;l < NS;l++)
120                     {
121                         dp[i][next[j][l]][k|tag[next[j][l]]] += dp[i-1][j][k];
122                         dp[i][next[j][l]][k|tag[next[j][l]]] %= MOD;
123                     }
124                 }
125 int ans =0;
126 for (int i =0;i <1<< M;i++)
127 if (bitCount(i) >= K)
128 for (int j =0;j < node;j++)
129                 {
130                     ans += dp[N][j][i];
131                     ans %= MOD;
132                 }
133         printf("%d\n",ans);
134     }
135 return0;
136 }