HDUOJ 2222 Keywords Search

第一次写AC自动机。

#ifdef _DEBUG#pragma warning(disable : 4996)#endif#include <iostream>#include <string>#include <vector>#include <stack>#include <queue>#include <deque>#include <set>#include <map>#include <algorithm>#include <functional>#include <sstream>#include <utility>#include <cstring>#include <cstdio>#include <cstdlib>#include <ctime>#include <cmath>#include <cctype>#define CLEAR(a, b) memset(a, b, sizeof(a))#define CLOSE() ios::sync_with_stdio(false)#define IN() freopen("in.txt", "r", stdin)#define OUT() freopen("out.txt", "w", stdout)#define PF(a) printf("%d\n", a)#define SF(a) scanf("%d", &a)#define SFF(a, b) scanf("%d%d", &a, &b)#define SFFF(a, b, c) scanf("%d%d%d", &a, &b, &c)#define FOR(i, a, b) for(int i = a; i < b; ++i)#define LL long long#define maxn 100005#define maxm 10005#define MOD  10007#define INF 10007using namespace std;//-------------------------CHC------------------------------//struct Node {int end = 0;Node *son[26], *fail;Node() {fail = NULL;FOR(i, 0, 26) son[i] = NULL;}};void add(char *s, Node *root) {Node *cur = root;while (*s) {int id = *s - 'a';if (!cur->son[id]) cur->son[id] = new Node;cur = cur->son[id];++s;}cur->end++;}void GetFail(Node *root) {queue<Node *> q;FOR(i, 0, 26) if (root->son[i])root->son[i]->fail = root, q.push(root->son[i]);while (q.size()) {Node *parent = q.front();q.pop();FOR(i, 0, 26) {if (parent->son[i]) {Node *son = parent->son[i];q.push(son);Node *t = parent->fail;while (t) {if (t->son[i]) {son->fail = t->son[i]; break;}t = t->fail;}if (!t) son->fail = root;}}}}int solve(char *s, Node *root) {int ret = 0;Node *pre = root, *cur;while (*s) {int id = *s - 'a';if (pre->son[id]) {cur = pre->son[id];while (cur != root) {if (cur->end >= 0) ret += cur->end, cur->end = -1;else break;cur = cur->fail;}pre = pre->son[id];++s;}else {if (pre == root) ++s;else pre = pre->fail;}}return ret;}void _free(Node *root) {if (root) {FOR(i, 0, 26) _free(root->son[i]);delete root;}}char s[1000005], t[55];int main() {int T;SF(T);while (T--) {Node *root = new Node;int n;SF(n);FOR(i, 0, n) {scanf("%s", t);add(t, root);}scanf("%s", s);GetFail(root);PF(solve(s, root));_free(root);}return 0;}