自己写的0.0
1 #include <queue> 2 #include <cstring> 3 #include <cstdio> 4 using namespace std; 5 6 struct AC_auto 7 { 8 const static int LetterSize = 26; 9 const static int TrieSize = 26 * ( 1e5 + 50); 10 11 int tot,root,fail[TrieSize],end[TrieSize],next[TrieSize][LetterSize]; 12 13 int newnode(void) 14 { 15 memset(next[tot],-1,sizeof(next[tot])); 16 end[tot] = 0; 17 return tot++; 18 } 19 20 void init(void) 21 { 22 tot = 0; 23 root = newnode(); 24 } 25 26 int getidx(char x) 27 { 28 return x - 'a'; 29 } 30 31 void insert(char *ss) 32 { 33 int len = strlen(ss); 34 int now = root; 35 for(int i = 0; i < len; i++) 36 { 37 int idx = getidx(ss[i]); 38 if(next[now][idx] == -1) 39 next[now][idx] = newnode(); 40 now = next[now][idx]; 41 } 42 end[now]++; 43 } 44 45 void build(void) 46 { 47 queue<int>Q; 48 fail[root] = root; 49 for(int i = 0; i < LetterSize; i++) 50 if(next[root][i] == -1) 51 next[root][i] = root; 52 else 53 fail[next[root][i]] = root,Q.push(next[root][i]); 54 while(Q.size()) 55 { 56 int now = Q.front();Q.pop(); 57 for(int i = 0; i < LetterSize; i++) 58 if(next[now][i] == -1) next[now][i] = next[fail[now]][i]; 59 else 60 fail[next[now][i]] = next[fail[now]][i],Q.push(next[now][i]); 61 } 62 } 63 64 int match(char *ss) 65 { 66 int len,now,res; 67 len = strlen(ss),now = root,res = 0; 68 for(int i = 0; i < len; i++) 69 { 70 int idx = getidx(ss[i]); 71 int tmp = now = next[now][idx]; 72 while(tmp) 73 { 74 res += end[tmp]; 75 end[tmp] = 0;//按题目修改 76 tmp = fail[tmp]; 77 } 78 } 79 return res; 80 } 81 void debug() 82 { 83 for(int i = 0;i < tot;i++) 84 { 85 printf("id = %3d,fail = %3d,end = %3d,chi = [",i,fail[i],end[i]); 86 for(int j = 0;j < LetterSize;j++) 87 printf("%3d",next[i][j]); 88 printf("] "); 89 } 90 } 91 }; 92 int main(void) 93 { 94 95 96 return 0; 97 }
从网上扒的：
//====================== // HDU 2222 // 求目标串中出现了几个模式串 //==================== #include <stdio.h> #include <algorithm> #include <iostream> #include <string.h> #include <queue> using namespace std; struct Trie { int next[500010][26],fail[500010],end[500010]; int root,L; int newnode() { for(int i = 0;i < 26;i++) next[L][i] = -1; end[L++] = 0; return L-1; } void init() { L = 0; root = newnode(); } void insert(char buf[]) { int len = strlen(buf); int now = root; for(int i = 0;i < len;i++) { if(next[now][buf[i]-'a'] == -1) next[now][buf[i]-'a'] = newnode(); now = next[now][buf[i]-'a']; } end[now]++; } void build() { queue<int>Q; fail[root] = root; for(int i = 0;i < 26;i++) if(next[root][i] == -1) next[root][i] = root; else { fail[next[root][i]] = root; Q.push(next[root][i]); } while( !Q.empty() ) { int now = Q.front(); Q.pop(); for(int i = 0;i < 26;i++) if(next[now][i] == -1) next[now][i] = next[fail[now]][i]; else { fail[next[now][i]]=next[fail[now]][i]; Q.push(next[now][i]); } } } int query(char buf[]) { int len = strlen(buf); int now = root; int res = 0; for(int i = 0;i < len;i++) { now = next[now][buf[i]-'a']; int temp = now; while( temp != root ) { res += end[temp]; end[temp] = 0; temp = fail[temp]; } } return res; } void debug() { for(int i = 0;i < L;i++) { printf("id = %3d,fail = %3d,end = %3d,chi = [",i,fail[i],end[i]); for(int j = 0;j < 26;j++) printf("%2d",next[i][j]); printf("] "); } } }; char buf[1000010]; Trie ac; int main() { int T; int n; scanf("%d",&T); while( T-- ) { scanf("%d",&n); ac.init(); for(int i = 0;i < n;i++) { scanf("%s",buf); ac.insert(buf); } ac.build(); scanf("%s",buf); printf("%d ",ac.query(buf)); } return 0; }
struct AC_Auto{ const static int LetterSize = 26; const static int TrieSize = 26 * ( 1e5 + 50); int tot; int fail[TrieSize]; int suffixlink[TrieSize]; struct node{ int ptr[LetterSize]; int val; }tree[TrieSize]; inline int GetLetterIdx(char c){ return c - 'a'; } void init_node(node & s){ memset( s.ptr , 0 , sizeof( s.ptr ) ); s.val = 0; } void find(const char * str){ int len = strlen( str ); int j = 0; for(int i = 0 ; i < len ; ++ i){ int idx = GetLetterIdx( str[i] ); while(j && !tree[j].ptr[idx]) j = fail[j]; j = tree[j].ptr[idx]; if(suffixlink[j]) minv[i] = suffixlink[j]; else minv[i] = 0; } } void insert(const char * str){ int len = strlen( str ); int cur = 0; for(int i = 0 ; i < len ; ++ i){ int idx = GetLetterIdx( str[i] ); if(!tree[cur].ptr[idx]){ tree[cur].ptr[idx] = tot; init_node( tree[tot++] ); } cur = tree[cur].ptr[idx]; } if(tree[cur].val == 0) tree[cur].val = len; else tree[cur].val = min( tree[cur].val , len ); } void build_fail(){ queue < int > Q; // 开在栈中 , 如果节点数较多 , 可设为全局变量 suffixlink[0] = fail[0] = 0; for(int i = 0 ; i < LetterSize ; ++ i) if(tree[0].ptr[i]){ int index = tree[0].ptr[i]; fail[index] = 0 , suffixlink[index] = tree[index].val; Q.push( index ); } while(!Q.empty()){ int x = Q.front() ; Q.pop(); for(int i = 0 ; i < LetterSize ; ++ i) if(tree[x].ptr[i]){ int v = tree[x].ptr[i]; int j = fail[x]; while( j && !tree[j].ptr[i] ) j = fail[j]; fail[v] = tree[j].ptr[i]; suffixlink[v] = suffixlink[fail[v]]; if(suffixlink[v] == 0){ if(suffixlink[x]) suffixlink[v] = suffixlink[x] + 1; } else if(suffixlink[x]) suffixlink[v] = min( suffixlink[v] , suffixlink[x] + 1 ); if(tree[v].val){ if(suffixlink[v]==0) suffixlink[v] = tree[v].val; else suffixlink[v] = min( suffixlink[v] , tree[v].val ); } Q.push( v ); } } } void init(){ tot = 1 ; init_node( tree[0] );} }ac_auto;