hdu 2222 Keywords Search ac自动机模板

题目链接

先整理一发ac自动机模板..

#include <iostream>
#include <vector>
#include <cstdio>
#include <cstring>
#include <algorithm>
#include <complex>
#include <cmath>
#include <map>
#include <set>
#include <string>
#include <queue>
#include <stack>
#include <bitset>
using namespace std;
#define pb(x) push_back(x)
#define ll long long
#define mk(x, y) make_pair(x, y)
#define lson l, m, rt<<1
#define mem(a) memset(a, 0, sizeof(a))
#define rson m+1, r, rt<<1|1
#define mem1(a) memset(a, -1, sizeof(a))
#define mem2(a) memset(a, 0x3f, sizeof(a))
#define rep(i, n, a) for(int i = a; i<n; i++)
#define fi first
#define se second
typedef complex <double> cmx;
typedef pair<int, int> pll;
const double PI = acos(-1.0);
const double eps = 1e-8;
const int mod = 1e9+7;
const int inf = 1061109567;
const int dir[][2] = { {-1, 0}, {1, 0}, {0, -1}, {0, 1} };
const int maxn = 5e5+5;
struct AC
{
    int nxt[maxn][26], fail[maxn], end[maxn];
    int root, len;
    int node() {
        mem1(nxt[len]);
        end[len++] = 0;
        return len-1;
    }
    void init() {
        len = 0;
        root = node();
    }
    void insert(char str[]) {
        int l = strlen(str);
        int now = root;
        for(int i = 0; i < l; i++) {
            if(nxt[now][str[i]-'a'] == -1) {
                nxt[now][str[i]-'a'] = node();
            }
            now = nxt[now][str[i]-'a'];
        }
        end[now]++;
    }
    void build() {
        queue <int> q;
        fail[root] = root;
        for(int i = 0; i < 26; i++) {
            if(nxt[root][i] == -1) {
                nxt[root][i] = root;
            } else {
                fail[nxt[root][i]] = root;
                q.push(nxt[root][i]);
            }
        }
        while(!q.empty()) {
            int now = q.front(); q.pop();
            for(int i = 0; i < 26; i++) {
                if(nxt[now][i] == -1) {
                    nxt[now][i] = nxt[fail[now]][i];
                } else {
                    fail[nxt[now][i]] = nxt[fail[now]][i];
                    q.push(nxt[now][i]);
                }
            }
        }
    }
    int query(char str[]) {
        int l = strlen(str);
        int now = root, ans = 0;
        for(int i = 0; i < l; i ++) {
            now = nxt[now][str[i]-'a'];
            int tmp = now;
            while(tmp != root) {
                ans += end[tmp];
                end[tmp] = 0;
                tmp = fail[tmp];
            }
        }
        return ans;
    }
}ac;
char s[1000005];
int main()
{
    int t, n;
    cin>>t;
    while(t--) {
        ac.init();
        scanf("%d", &n);
        for(int i = 0; i < n; i++) {
            scanf("%s", s);
            ac.insert(s);
        }
        ac.build();
        scanf("%s", s);
        printf("%d
", ac.query(s));
    }
    return 0;
}