AC自动机

Aho-Corasick-Automation.cpp

@@ -0,0 +1,131 @@
+#include <cstdio>
+#include <cstring>
+#include <queue>
+
+#define NIL 0
+#define ALPHABET_SIZE 26
+#define STRING_LENGTH 100000
+#define PATTERN_COUNT 1000
+#define PATTERN_LENGTH 1000
+#define NODE_COUNT 100000
+
+using namespace std;
+
+struct node
+{
+	int id;
+	node *next[ALPHABET_SIZE], *fail, *last;
+	node();
+}*root;
+
+int idc = 0;
+char s[PATTERN_COUNT][PATTERN_LENGTH], t[STRING_LENGTH];
+int len[PATTERN_COUNT];
+
+node::node() : id(0), fail(NIL), last(NIL)
+{
+	memset(next, 0, sizeof(next));
+}
+
+void init_trie()
+{
+	root = new node;
+}
+
+void insert(char *s)
+{
+	int l = strlen(s), x;
+	node *cur = root;
+	for (int i = 0; i < l; i++)
+	{
+		x = s[i] - 'a';
+		if (cur->next[x] == NIL)
+		{
+			cur->next[x] = new node;
+		}
+		cur = cur->next[x];
+	}
+	cur->id = ++idc;
+}
+
+void init_fail()
+{
+	queue<node*> Q;
+	root->fail = root;
+	root->last = root;
+	for (int i = 0; i < ALPHABET_SIZE; i++)
+	{
+		if (root->next[i] != NIL)
+		{
+			root->next[i]->fail = root;
+			root->next[i]->last = root;
+			Q.push(root->next[i]);
+		}
+		else
+		{
+			root->next[i] = root;
+		}
+	}
+	while (!Q.empty())
+	{
+		node *cur = Q.front();
+		Q.pop();
+		for (int i = 0; i < ALPHABET_SIZE; i++)
+		{
+			if (cur->next[i] != NIL)
+			{
+				cur->next[i]->fail = cur->fail->next[i];
+				cur->next[i]->last = cur->next[i]->fail->id > 0 ? cur->next[i]->fail : cur->next[i]->fail->last;
+				Q.push(cur->next[i]);
+			}
+			else
+			{
+				cur->next[i] = cur->fail->next[i];
+			}
+		}
+	}
+}
+
+void print(node *cur, int shift)
+{
+	while (cur != root)
+	{
+		printf("matched with shift %2d : %s\n", shift - len[cur->id] + 1, s[cur->id]);
+		cur = cur->last;
+	}
+}
+
+void ac_automation()
+{
+	int l = strlen(t);
+	node *cur = root;
+	for (int i = 0; i < l; i++)
+	{
+		cur = cur->next[t[i] - 'a'];
+		if (cur->id > 0)
+		{
+			print(cur, i);
+		}
+		else
+		{
+			print(cur->last, i);
+		}
+	}
+}
+
+int main()
+{
+	int n;
+	scanf("%s", t);
+	scanf("%d", &n);
+	init_trie();
+	for (int i = 1; i <= n; i++)
+	{
+		scanf("%s", s[i]);
+		len[i] = strlen(s[i]);
+		insert(s[i]);
+	}
+	init_fail();
+	ac_automation();
+	return 0;
+}