做题，
1 #include <cstdio> 2 #include <string> 3 #include <cstring> 4 using namespace std; 5 #define MOD 20090717 6 int trie[351][26]; 7 int o[351]; 8 int fail[351]; 9 int que[351]; 10 int dp[2][351][1024]; 11 int flag[1024]; 12 int t; 13 void CL() 14 { 15 memset(trie,-1,sizeof(trie)); 16 memset(dp,0,sizeof(dp)); 17 memset(o,0,sizeof(o)); 18 t = 1; 19 } 20 void insert(char *s,int num) 21 { 22 int root,i,len; 23 len = strlen(s); 24 root = 0; 25 for(i = 0;i < len;i ++) 26 { 27 if(trie[root][s[i]-'a'] == -1) 28 trie[root][s[i]-'a'] = t ++; 29 root = trie[root][s[i]-'a']; 30 } 31 o[root] |= 1<<num; 32 } 33 void build_ac() 34 { 35 int head,tail,front,i; 36 head = tail = 0; 37 for(i = 0;i < 26;i ++) 38 { 39 if(trie[0][i] != -1) 40 { 41 fail[trie[0][i]] = 0; 42 que[tail++] = trie[0][i]; 43 } 44 else 45 { 46 trie[0][i] = 0; 47 } 48 } 49 while(head != tail) 50 { 51 front = que[head++]; 52 o[front] |= o[fail[front]]; 53 for(i = 0;i < 26;i ++) 54 { 55 if(trie[front][i] != -1) 56 { 57 que[tail++] = trie[front][i]; 58 fail[trie[front][i]] = trie[fail[front]][i]; 59 } 60 else 61 { 62 trie[front][i] = trie[fail[front]][i]; 63 } 64 } 65 } 66 } 67 int main() 68 { 69 int n,m,r,k,i,j,u,x,y; 70 char str[101]; 71 for(i = 0;i < 1024;i ++) 72 { 73 for(j = 0;j < 10;j ++) 74 { 75 if(i&(1<<j)) flag[i] ++; 76 } 77 } 78 while(scanf("%d%d%d",&n,&m,&r)!=EOF) 79 { 80 if(n == 0&&m == 0&&r == 0) break; 81 CL(); 82 for(i = 0;i < m;i ++) 83 { 84 scanf("%s",str); 85 insert(str,i); 86 } 87 build_ac(); 88 dp[0][0][0] = 1; 89 x = 0;y = 1; 90 for(i = 0;i < n;i ++) 91 { 92 memset(dp[y],0,sizeof(dp[y])); 93 for(j = 0;j < t;j ++) 94 { 95 for(k = 0;k < (1<<m);k ++) 96 { 97 if(dp[x][j][k] == 0) continue; 98 for(u = 0;u < 26;u ++) 99 { 100 int temp = trie[j][u]; 101 dp[y][temp][k|o[temp]] += dp[x][j][k]; 102 if(dp[y][temp][k|o[temp]] >= MOD) 103 dp[y][temp][k|o[temp]] -= MOD; 104 } 105 } 106 } 107 swap(x,y); 108 } 109 int ans = 0; 110 for(i = 0;i < t;i ++) 111 { 112 for(j = 0;j < (1<<m);j ++) 113 { 114 if(flag[j] >= r) 115 ans = (ans + dp[x][i][j])%MOD; 116 } 117 } 118 printf("%d ",ans); 119 } 120 return 0; 121 }
找找手感。