【模板】AC自动机

模板1

#include <queue>
#include <cstdio>
#include <cstring>
#define N 1000001

int n, cnt, ans;
int next[N][26], val[N], fail[N];
char s[N];
std::queue <int> q;

inline void insert()
{
	int i, x, now = 0, m = strlen(s + 1);
	for(i = 1; i <= m; i++)
	{
		x = s[i] - 'a';
		if(!next[now][x])
			next[now][x] = ++cnt;
		now = next[now][x];
	}
	val[now]++;
}

inline void make_fail()
{
	int i, now;
	for(i = 0; i < 26; i++)
		if(next[0][i])
			q.push(next[0][i]);
	while(!q.empty())
	{
		now = q.front();
		q.pop();
		for(i = 0; i < 26; i++)
		{
			if(!next[now][i])
			{
				next[now][i] = next[fail[now]][i];
				continue;
			}
			fail[next[now][i]] = next[fail[now]][i];
			q.push(next[now][i]);
		}
	}
}

inline void ac()
{
	int i, j, now = 0, m = strlen(s + 1);
	for(i = 1; i <= m; i++)
	{
		now = next[now][s[i] - 'a'];
		for(j = now; j && ~val[j]; j = fail[j])
		{
			ans += val[j];
			val[j] = -1;
		}
	}
}

int main()
{
	int i;
	scanf("%d", &n);
	for(i = 1; i <= n; i++)
	{
		scanf("%s", s + 1);
		insert();
	}
	make_fail();
	scanf("%s", s + 1);
	ac();
	printf("%d
", ans);
	return 0;
}

　　

模板2

#include <queue>
#include <cstdio>
#include <cstring>
#define N 1000001
#define max(x, y) ((x) > (y) ? (x) : (y))

int n, cnt;
int val[N], next[N][26], ans[N], fail[N];
char s1[151][71], s2[N];
std::queue <int> q;

inline void insert(int k, char *s)
{
	int i, x, now = 0, m = strlen(s + 1);
	for(i = 1; i <= m; i++)
	{
		x = s[i] - 'a';
		if(!next[now][x])
			next[now][x] = ++cnt;
		now = next[now][x];
	}
	val[now] = k;
}

inline void make_fail()
{
	int i, now;
	for(i = 0; i < 26; i++)
		if(next[0][i])
			q.push(next[0][i]);
	while(!q.empty())
	{
		now = q.front();
		q.pop();
		for(i = 0; i < 26; i++)
		{
			if(!next[now][i])
			{
				next[now][i] = next[fail[now]][i];
				continue;
			}
			fail[next[now][i]] = next[fail[now]][i];
			q.push(next[now][i]);
		}
	}
}

inline void ac(char *s)
{
	int i, j, now = 0, m = strlen(s + 1);
	for(i = 1; i <= m; i++)
	{
		now = next[now][s[i] - 'a'];
		for(j = now; j; j = fail[j])
			if(val[j])
				ans[val[j]]++;
	}
	for(i = 1; i <= n; i++)
		ans[0] = max(ans[0], ans[i]);
	printf("%d
", ans[0]);
	for(i = 1; i <= n; i++)
		if(ans[i] == ans[0])
			printf("%s
", s1[i] + 1);
}

int main()
{
	int i;
	while(scanf("%d", &n) && n)
	{
		cnt = 0;
		memset(val, 0, sizeof(val));
		memset(ans, 0, sizeof(ans));
		memset(next, 0, sizeof(next));
		memset(fail, 0, sizeof(fail));
		for(i = 1; i <= n; i++)
		{
			scanf("%s", s1[i] + 1);
			insert(i, s1[i]);
		}
		make_fail();
		scanf("%s", s2 + 1);
		ac(s2);
	}
	return 0;
}