AC自动机 模板题 HDU-2222 Keywords Search
1 #include<bits/stdc++.h> 2 using namespace std; 3 #define LL long long 4 #define ULL unsigned LL 5 #define fi first 6 #define se second 7 #define lson l,m,rt<<1 8 #define rson m+1,r,rt<<1|1 9 #define max3(a,b,c) max(a,max(b,c)) 10 #define min3(a,b,c) min(a,min(b,c)) 11 const int INF = 0x3f3f3f3f; 12 const LL mod = 1e9+7; 13 typedef pair<int,int> pll; 14 const int N = 1e5+10, M = 1e3; 15 char str[N*10]; 16 int trie[N*10][26]; 17 int fair[N*26]; 18 int cnt[N*26]; 19 int tot = 2; 20 void Insert(){ 21 int rt = 1, len = strlen(str); 22 for(int i = 0; i < len; i++){ 23 int id = str[i] - 'a'; 24 if(trie[rt][id] == 0){ 25 cnt[tot] = 0; 26 fair[tot] = 0; 27 trie[rt][id] = tot++; 28 } 29 rt = trie[rt][id]; 30 } 31 cnt[rt]++; 32 } 33 void Build_tree(){ 34 queue<int> q; 35 q.push(1); 36 int p; 37 while(!q.empty()){ 38 int tmp = q.front(); 39 q.pop(); 40 for(int i = 0; i < 26; i++){ 41 if(trie[tmp][i] != 0){ 42 if(tmp == 1) 43 fair[trie[tmp][i]] = 1; 44 else{ 45 p = fair[tmp]; 46 while(p){ 47 if(trie[p][i]){ 48 fair[trie[tmp][i]] = trie[p][i]; 49 break; 50 } 51 else p = fair[p]; 52 } 53 if(!p) fair[trie[tmp][i]] = 1; 54 } 55 q.push(trie[tmp][i]); 56 } 57 } 58 } 59 } 60 int Query(){ 61 int rt = 1, ret = 0, len = strlen(str); 62 for(int i = 0; i < len; i++){ 63 int id = str[i] - 'a'; 64 while(!trie[rt][id] && rt != 1) rt = fair[rt]; 65 rt = trie[rt][id]; 66 if(rt == 0) rt = 1; 67 int tmp = rt; 68 while(tmp != 1){ 69 if(cnt[tmp] >= 0){ 70 ret += cnt[tmp]; 71 cnt[tmp] = -1; 72 } 73 else break; 74 tmp = fair[tmp]; 75 } 76 } 77 return ret; 78 } 79 void init(){ 80 for(int i = 1; i < tot; i++){ 81 for(int j = 0; j < 26; j++) 82 trie[i][j] = 0; 83 } 84 tot = 2; 85 } 86 int main(){ 87 int T; 88 scanf("%d", &T); 89 while(T--){ 90 init(); 91 int n; 92 scanf("%d", &n); 93 while(n--){ 94 scanf("%s", str); 95 Insert(); 96 } 97 Build_tree(); 98 scanf("%s", str); 99 printf("%d ", Query()); 100 } 101 return 0; 102 }
2进制分组AC自动机
假如给你21个串： 分为 16+4+1，再添加一个串的时候，即21+1， 22 = 16+4+1+1 = 16 + 4 + 2。 这样每次加串之后只会有logn个操作，查询也变成logn操作， 对于同一个串建立fair指针的次数就少了。
1 #include<bits/stdc++.h> 2 using namespace std; 3 #define Fopen freopen("_in.txt","r",stdin); freopen("_out.txt","w",stdout); 4 #define LL long long 5 #define ULL unsigned LL 6 #define fi first 7 #define se second 8 #define pb push_back 9 #define lson l,m,rt<<1 10 #define rson m+1,r,rt<<1|1 11 #define max3(a,b,c) max(a,max(b,c)) 12 #define min3(a,b,c) min(a,min(b,c)) 13 typedef pair<int,int> pll; 14 const int INF = 0x3f3f3f3f; 15 const LL mod = (int)1e9+7; 16 const int N = 3e5 + 100; 17 struct Node{ 18 static const int m = 26;static const int KN = N; 19 int next[KN][m], fair[KN], tot = 0, mark[KN], mark1[KN], root[20], cnt = 0, si[20]; 20 void Build(int x){ 21 queue<int> q; 22 q.push(x); 23 int pos, p, v; 24 while(!q.empty()){ 25 pos = q.front(), q.pop(); 26 for(int i = 0; i < m; i++){ 27 if(!next[pos][i]) continue; 28 p = fair[pos]; v = next[pos][i]; 29 while(p && !next[p][i]) p = fair[p]; 30 if(p) fair[v] = next[p][i]; 31 else fair[v] = x; 32 q.push(v); 33 mark1[v] = mark1[fair[v]] + mark[v]; 34 } 35 } 36 } 37 void Add(char s[], char ch){ 38 root[++cnt] = ++tot; si[cnt] = 1; 39 int pos = root[cnt]; 40 for(int i = 0; s[i]; i++){ 41 if(!next[pos][s[i]-ch]) next[pos][s[i]-ch] = ++tot; 42 pos = next[pos][s[i]-ch]; 43 } 44 mark[pos]++; 45 while(si[cnt] == si[cnt-1]){ 46 Unit(root[cnt-1], root[cnt]); 47 si[--cnt] *= 2; 48 } 49 Build(root[cnt]); 50 } 51 int Query(char s[], char ch){ 52 int pos, ret = 0; 53 for(int id = 1; id <= cnt; id++){ 54 pos = root[id]; 55 for(int i = 0; s[i]; i++){ 56 while(pos && !next[pos][s[i]-ch]) pos = fair[pos]; 57 if(pos) pos = next[pos][s[i]-ch]; 58 else pos = root[id]; 59 ret += mark1[pos]; 60 } 61 } 62 return ret; 63 } 64 void Unit(int u, int v){ 65 mark[u] += mark[v]; 66 for(int i = 0; i < m; i++){ 67 if(!next[u][i] || !next[v][i]) next[u][i] += next[v][i]; 68 else Unit(next[u][i], next[v][i]); 69 } 70 } 71 }ac[2]; 72 char str[N]; 73 int main(){ 74 int n, k; 75 scanf("%d", &n); 76 while(n--){ 77 scanf("%d%s", &k, str); 78 if(k <= 2) ac[k-1].Add(str, 'a'); 79 else { 80 printf("%d ", ac[0].Query(str, 'a')-ac[1].Query(str, 'a')); 81 fflush(stdout); 82 } 83 } 84 return 0; 85 } 86 87 AC自动机